Impl n_to_one and one_to_n (up to 4) with tests

.gitignore

@@ -0,0 +1,3 @@
+UnitTests
+src/*.o
+src/tests/*.o

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "third_party/Catch2"]
+	path = third_party/Catch2
+	url = https://github.com/catchorg/Catch2.git

Makefile

@@ -0,0 +1,14 @@
+CFLAGS = -Wall -Wextra -Wpedantic
+CXXFLAGS = -Wall -Wextra -Wpedantic -Ithird_party/Catch2/single_include/catch2
+
+all: UnitTests
+
+UnitTests: src/n_to_one.o src/tests/test_main.o src/tests/test_n_to_one.o
+	$(CXX) $(CXXFLAGS) -o UnitTests $^
+
+.PHONY:
+
+clean:
+	rm -f UnitTests
+	rm -f src/*.o
+	rm -f src/tests/*.o

src/n_to_one.c

@@ -0,0 +1,125 @@
+#include "n_to_one.h"
+
+unsigned long two_to_one(
+        unsigned long x,
+        unsigned long y,
+        unsigned long x_width) {
+    return x + y * x_width;
+}
+
+void one_to_two(
+        unsigned long idx,
+        unsigned long *x,
+        unsigned long *y,
+        unsigned long x_width) {
+    *x = idx % x_width;
+    *y = idx / x_width;
+}
+
+unsigned long three_to_one(
+        unsigned long x,
+        unsigned long y,
+        unsigned long z,
+        unsigned long x_width,
+        unsigned long y_width){
+    return x + y * x_width + z * x_width * y_width;
+}
+
+void one_to_three(
+        unsigned long idx,
+        unsigned long *x,
+        unsigned long *y,
+        unsigned long *z,
+        unsigned long x_width,
+        unsigned long y_width) {
+    *x = idx % x_width;
+    *y = (idx / x_width) % y_width;
+    *z = idx / x_width / y_width;
+}
+
+unsigned long four_to_one(
+        unsigned long x,
+        unsigned long y,
+        unsigned long z,
+        unsigned long i,
+        unsigned long x_width,
+        unsigned long y_width,
+        unsigned long z_width) {
+    return x + y * x_width + z * x_width * y_width + i * x_width * y_width * z_width;
+}
+void one_to_four(
+        unsigned long idx,
+        unsigned long *x,
+        unsigned long *y,
+        unsigned long *z,
+        unsigned long *i,
+        unsigned long x_width,
+        unsigned long y_width,
+        unsigned long z_width) {
+    *x = idx % x_width;
+    *y = (idx / x_width) % y_width;
+    *z = ((idx / x_width) / y_width) % z_width;
+    *i = ((idx / x_width) / y_width) / z_width;
+}
+
+unsigned long long two_to_one_l(
+        unsigned long long x,
+        unsigned long long y,
+        unsigned long long x_width) {
+    return x + y * x_width;
+}
+
+void one_to_two_l(
+        unsigned long long idx,
+        unsigned long long *x,
+        unsigned long long *y,
+        unsigned long long x_width) {
+    *x = idx % x_width;
+    *y = idx / x_width;
+}
+
+unsigned long long three_to_one_l(
+        unsigned long long x,
+        unsigned long long y,
+        unsigned long long z,
+        unsigned long long x_width,
+        unsigned long long y_width){
+    return x + y * x_width + z * x_width * y_width;
+}
+
+void one_to_three_l(
+        unsigned long long idx,
+        unsigned long long *x,
+        unsigned long long *y,
+        unsigned long long *z,
+        unsigned long long x_width,
+        unsigned long long y_width) {
+    *x = idx % x_width;
+    *y = (idx / x_width) % y_width;
+    *z = idx / x_width / y_width;
+}
+
+unsigned long long four_to_one_l(
+        unsigned long long x,
+        unsigned long long y,
+        unsigned long long z,
+        unsigned long long i,
+        unsigned long long x_width,
+        unsigned long long y_width,
+        unsigned long long z_width) {
+    return x + y * x_width + z * x_width * y_width + i * x_width * y_width * z_width;
+}
+void one_to_four_l(
+        unsigned long long idx,
+        unsigned long long *x,
+        unsigned long long *y,
+        unsigned long long *z,
+        unsigned long long *i,
+        unsigned long long x_width,
+        unsigned long long y_width,
+        unsigned long long z_width) {
+    *x = idx % x_width;
+    *y = (idx / x_width) % y_width;
+    *z = ((idx / x_width) / y_width) % z_width;
+    *i = ((idx / x_width) / y_width) / z_width;
+}

src/n_to_one.h

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+#ifndef MULTIDIMENSIONAL_TO_ONE_H
+#define MULTIDIMENSIONAL_TO_ONE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+unsigned long two_to_one(
+    unsigned long x,
+    unsigned long y,
+    unsigned long x_width);
+void one_to_two(
+    unsigned long idx,
+    unsigned long *x,
+    unsigned long *y,
+    unsigned long x_width);
+
+unsigned long three_to_one(
+    unsigned long x,
+    unsigned long y,
+    unsigned long z,
+    unsigned long x_width,
+    unsigned long y_width);
+void one_to_three(
+    unsigned long idx,
+    unsigned long *x,
+    unsigned long *y,
+    unsigned long *z,
+    unsigned long x_width,
+    unsigned long y_width);
+
+unsigned long four_to_one(
+    unsigned long x,
+    unsigned long y,
+    unsigned long z,
+    unsigned long i,
+    unsigned long x_width,
+    unsigned long y_width,
+    unsigned long z_width);
+void one_to_four(
+    unsigned long idx,
+    unsigned long *x,
+    unsigned long *y,
+    unsigned long *z,
+    unsigned long *i,
+    unsigned long x_width,
+    unsigned long y_width,
+    unsigned long z_width);
+
+unsigned long long two_to_one_l(
+    unsigned long long x,
+    unsigned long long y,
+    unsigned long long x_width);
+void one_to_two_l(
+    unsigned long long idx,
+    unsigned long long *x,
+    unsigned long long *y,
+    unsigned long long x_width);
+
+unsigned long long three_to_one_l(
+    unsigned long long x,
+    unsigned long long y,
+    unsigned long long z,
+    unsigned long long x_width,
+    unsigned long long y_width);
+void one_to_three_l(
+    unsigned long long idx,
+    unsigned long long *x,
+    unsigned long long *y,
+    unsigned long long *z,
+    unsigned long long x_width,
+    unsigned long long y_width);
+
+unsigned long long four_to_one_l(
+    unsigned long long x,
+    unsigned long long y,
+    unsigned long long z,
+    unsigned long long i,
+    unsigned long long x_width,
+    unsigned long long y_width,
+    unsigned long long z_width);
+void one_to_four_l(
+    unsigned long long idx,
+    unsigned long long *x,
+    unsigned long long *y,
+    unsigned long long *z,
+    unsigned long long *i,
+    unsigned long long x_width,
+    unsigned long long y_width,
+    unsigned long long z_width);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

src/tests/test_main.cpp

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+#define CATCH_CONFIG_MAIN
+#include <catch.hpp>

src/tests/test_n_to_one.cpp

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+#include <catch.hpp>
+
+#include "../n_to_one.h"
+
+struct Indices {
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long z;
+    unsigned long long i;
+};
+
+TEST_CASE("two_to_one", "n_to_one") {
+    unsigned long x = 5;
+    unsigned long y = 4;
+    unsigned long x_width = 10;
+
+    CHECK(two_to_one(x, y, x_width) == 45);
+
+    x = 3;
+    CHECK(two_to_one(x, y, x_width) == 43);
+
+    y = 7;
+    CHECK(two_to_one(x, y, x_width) == 73);
+}
+
+TEST_CASE("one_to_two", "n_to_one") {
+    unsigned long x;
+    unsigned long y;
+    unsigned long x_width = 10;
+    unsigned long idx = 45;
+
+    one_to_two(idx, &x, &y, x_width);
+    CHECK(x == 5);
+    CHECK(y == 4);
+
+    idx = 43;
+    one_to_two(idx, &x, &y, x_width);
+    CHECK(x == 3);
+    CHECK(y == 4);
+
+    idx = 73;
+    one_to_two(idx, &x, &y, x_width);
+    CHECK(x == 3);
+    CHECK(y == 7);
+}
+
+TEST_CASE("three_to_one", "n_to_one") {
+    unsigned long x = 5;
+    unsigned long y = 4;
+    unsigned long z = 3;
+    unsigned long x_width = 10;
+    unsigned long y_width = 10;
+
+    CHECK(three_to_one(x, y, z, x_width, y_width) == 345);
+
+    x = 3;
+    z = 7;
+    CHECK(three_to_one(x, y, z, x_width, y_width) == 743);
+
+    x = 1;
+    y = 5;
+    z = 9;
+    CHECK(three_to_one(x, y, z, x_width, y_width) == 951);
+}
+
+TEST_CASE("one_to_three", "n_to_one") {
+    unsigned long x;
+    unsigned long y;
+    unsigned long z;
+    unsigned long x_width = 10;
+    unsigned long y_width = 10;
+    unsigned long idx = 123;
+
+    one_to_three(idx, &x, &y, &z, x_width, y_width);
+    CHECK(x == 3);
+    CHECK(y == 2);
+    CHECK(z == 1);
+
+    idx = 957;
+    one_to_three(idx, &x, &y, &z, x_width, y_width);
+    CHECK(x == 7);
+    CHECK(y == 5);
+    CHECK(z == 9);
+
+    idx = 482;
+    one_to_three(idx, &x, &y, &z, x_width, y_width);
+    CHECK(x == 2);
+    CHECK(y == 8);
+    CHECK(z == 4);
+}
+
+TEST_CASE("four_to_one", "n_to_one") {
+    unsigned long x = 1;
+    unsigned long y = 2;
+    unsigned long z = 3;
+    unsigned long i = 4;
+    unsigned long x_width = 10;
+    unsigned long y_width = 10;
+    unsigned long z_width = 10;
+
+    CHECK(four_to_one(x, y, z, i, x_width, y_width, z_width) == 4321);
+
+    y_width = 5;
+    // 1 + 2 * 10 + 3 * 10 * 5 + 4 * 10 * 5 * 10 == 2171
+    CHECK(four_to_one(x, y, z, i, x_width, y_width, z_width) == 2171);
+
+    y_width = 10;
+    x = 9;
+    y = 7;
+    z = 4;
+    i = 2;
+    CHECK(four_to_one(x, y, z, i, x_width, y_width, z_width) == 2479);
+}
+
+TEST_CASE("one_to_four", "n_to_one") {
+    unsigned long x;
+    unsigned long y;
+    unsigned long z;
+    unsigned long i;
+    unsigned long x_width = 10;
+    unsigned long y_width = 10;
+    unsigned long z_width = 10;
+    unsigned long idx = 1234;
+
+    one_to_four(idx, &x, &y, &z, &i, x_width, y_width, z_width);
+    CHECK(x == 4);
+    CHECK(y == 3);
+    CHECK(z == 2);
+    CHECK(i == 1);
+
+    y_width = 5;
+    // x = 4, y = 3, z = 1234 / 10 / 5 % 10 == 4, i = 1234 / 10 / 5 / 10 == 2
+    one_to_four(idx, &x, &y, &z, &i, x_width, y_width, z_width);
+    CHECK(x == 4);
+    CHECK(y == 3);
+    CHECK(z == 4);
+    CHECK(i == 2);
+
+    y_width = 10;
+    idx = 7125;
+    one_to_four(idx, &x, &y, &z, &i, x_width, y_width, z_width);
+    CHECK(x == 5);
+    CHECK(y == 2);
+    CHECK(z == 1);
+    CHECK(i == 7);
+}
+
+TEST_CASE("n=2 objects long", "n_to_one") {
+    Indices indices[5*4];
+    unsigned long x;
+    unsigned long y;
+    unsigned long idx;
+
+    for(idx = 0; idx < 5*4; ++idx) {
+        one_to_two(idx, &x, &y, 5);
+        indices[idx].x = x;
+        indices[idx].y = y;
+    }
+
+    for(y = 0; y < 4; ++y) {
+        for(x = 0; x < 5; ++x) {
+            idx = two_to_one(x, y, 5);
+            REQUIRE(idx <= 5*4);
+            CHECK(indices[idx].x == x);
+            CHECK(indices[idx].y == y);
+        }
+    }
+}
+
+TEST_CASE("n=3 objects long", "n_to_one") {
+    Indices indices[5*4*3];
+    unsigned long x;
+    unsigned long y;
+    unsigned long z;
+    unsigned long idx;
+
+    for(idx = 0; idx < 5*4*3; ++idx) {
+        one_to_three(idx, &x, &y, &z, 5, 4);
+        indices[idx].x = x;
+        indices[idx].y = y;
+        indices[idx].z = z;
+    }
+
+    for(z = 0; z < 3; ++z) {
+        for(y = 0; y < 4; ++y) {
+            for(x = 0; x < 5; ++x) {
+                idx = three_to_one(x, y, z, 5, 4);
+                REQUIRE(idx <= 5*4*3);
+                CHECK(indices[idx].x == x);
+                CHECK(indices[idx].y == y);
+                CHECK(indices[idx].z == z);
+            }
+        }
+    }
+}
+
+TEST_CASE("n=4 objects long", "n_to_one") {
+    Indices indices[5*4*3*2];
+    unsigned long x;
+    unsigned long y;
+    unsigned long z;
+    unsigned long i;
+    unsigned long idx;
+
+    for(idx = 0; idx < 5*4*3*2; ++idx) {
+        one_to_four(idx, &x, &y, &z, &i, 5, 4, 3);
+        indices[idx].x = x;
+        indices[idx].y = y;
+        indices[idx].z = z;
+        indices[idx].i = i;
+    }
+
+    for(i = 0; i < 2; ++i) {
+        for(z = 0; z < 3; ++z) {
+            for(y = 0; y < 4; ++y) {
+                for(x = 0; x < 5; ++x) {
+                    idx = four_to_one(x, y, z, i, 5, 4, 3);
+                    REQUIRE(idx <= 5*4*3*2);
+                    CHECK(indices[idx].x == x);
+                    CHECK(indices[idx].y == y);
+                    CHECK(indices[idx].z == z);
+                    CHECK(indices[idx].i == i);
+                }
+            }
+        }
+    }
+}
+
+TEST_CASE("two_to_one_l", "n_to_one") {
+    unsigned long long x = 5;
+    unsigned long long y = 4;
+    unsigned long long x_width = 10;
+
+    CHECK(two_to_one_l(x, y, x_width) == 45);
+
+    x = 3;
+    CHECK(two_to_one_l(x, y, x_width) == 43);
+
+    y = 7;
+    CHECK(two_to_one_l(x, y, x_width) == 73);
+}
+
+TEST_CASE("one_to_two_l", "n_to_one") {
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long x_width = 10;
+    unsigned long long idx = 45;
+
+    one_to_two_l(idx, &x, &y, x_width);
+    CHECK(x == 5);
+    CHECK(y == 4);
+
+    idx = 43;
+    one_to_two_l(idx, &x, &y, x_width);
+    CHECK(x == 3);
+    CHECK(y == 4);
+
+    idx = 73;
+    one_to_two_l(idx, &x, &y, x_width);
+    CHECK(x == 3);
+    CHECK(y == 7);
+}
+
+TEST_CASE("three_to_one_l", "n_to_one") {
+    unsigned long long x = 5;
+    unsigned long long y = 4;
+    unsigned long long z = 3;
+    unsigned long long x_width = 10;
+    unsigned long long y_width = 10;
+
+    CHECK(three_to_one_l(x, y, z, x_width, y_width) == 345);
+
+    x = 3;
+    z = 7;
+    CHECK(three_to_one_l(x, y, z, x_width, y_width) == 743);
+
+    x = 1;
+    y = 5;
+    z = 9;
+    CHECK(three_to_one_l(x, y, z, x_width, y_width) == 951);
+}
+
+TEST_CASE("one_to_three_l", "n_to_one") {
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long z;
+    unsigned long long x_width = 10;
+    unsigned long long y_width = 10;
+    unsigned long long idx = 123;
+
+    one_to_three_l(idx, &x, &y, &z, x_width, y_width);
+    CHECK(x == 3);
+    CHECK(y == 2);
+    CHECK(z == 1);
+
+    idx = 957;
+    one_to_three_l(idx, &x, &y, &z, x_width, y_width);
+    CHECK(x == 7);
+    CHECK(y == 5);
+    CHECK(z == 9);
+
+    idx = 482;
+    one_to_three_l(idx, &x, &y, &z, x_width, y_width);
+    CHECK(x == 2);
+    CHECK(y == 8);
+    CHECK(z == 4);
+}
+
+TEST_CASE("four_to_one_l", "n_to_one") {
+    unsigned long long x = 1;
+    unsigned long long y = 2;
+    unsigned long long z = 3;
+    unsigned long long i = 4;
+    unsigned long long x_width = 10;
+    unsigned long long y_width = 10;
+    unsigned long long z_width = 10;
+
+    CHECK(four_to_one_l(x, y, z, i, x_width, y_width, z_width) == 4321);
+
+    y_width = 5;
+    // 1 + 2 * 10 + 3 * 10 * 5 + 4 * 10 * 5 * 10 == 2171
+    CHECK(four_to_one_l(x, y, z, i, x_width, y_width, z_width) == 2171);
+
+    y_width = 10;
+    x = 9;
+    y = 7;
+    z = 4;
+    i = 2;
+    CHECK(four_to_one_l(x, y, z, i, x_width, y_width, z_width) == 2479);
+}
+
+TEST_CASE("one_to_four_l", "n_to_one") {
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long z;
+    unsigned long long i;
+    unsigned long long x_width = 10;
+    unsigned long long y_width = 10;
+    unsigned long long z_width = 10;
+    unsigned long long idx = 1234;
+
+    one_to_four_l(idx, &x, &y, &z, &i, x_width, y_width, z_width);
+    CHECK(x == 4);
+    CHECK(y == 3);
+    CHECK(z == 2);
+    CHECK(i == 1);
+
+    y_width = 5;
+    // x = 4, y = 3, z = 1234 / 10 / 5 % 10 == 4, i = 1234 / 10 / 5 / 10 == 2
+    one_to_four_l(idx, &x, &y, &z, &i, x_width, y_width, z_width);
+    CHECK(x == 4);
+    CHECK(y == 3);
+    CHECK(z == 4);
+    CHECK(i == 2);
+
+    y_width = 10;
+    idx = 7125;
+    one_to_four_l(idx, &x, &y, &z, &i, x_width, y_width, z_width);
+    CHECK(x == 5);
+    CHECK(y == 2);
+    CHECK(z == 1);
+    CHECK(i == 7);
+}
+
+TEST_CASE("n=2 objects long long", "n_to_one") {
+    Indices indices[5*4];
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long idx;
+
+    for(idx = 0; idx < 5*4; ++idx) {
+        one_to_two_l(idx, &x, &y, 5);
+        indices[idx].x = x;
+        indices[idx].y = y;
+    }
+
+    for(y = 0; y < 4; ++y) {
+        for(x = 0; x < 5; ++x) {
+            idx = two_to_one_l(x, y, 5);
+            REQUIRE(idx <= 5*4);
+            CHECK(indices[idx].x == x);
+            CHECK(indices[idx].y == y);
+        }
+    }
+}
+
+TEST_CASE("n=3 objects long long", "n_to_one") {
+    Indices indices[5*4*3];
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long z;
+    unsigned long long idx;
+
+    for(idx = 0; idx < 5*4*3; ++idx) {
+        one_to_three_l(idx, &x, &y, &z, 5, 4);
+        indices[idx].x = x;
+        indices[idx].y = y;
+        indices[idx].z = z;
+    }
+
+    for(z = 0; z < 3; ++z) {
+        for(y = 0; y < 4; ++y) {
+            for(x = 0; x < 5; ++x) {
+                idx = three_to_one_l(x, y, z, 5, 4);
+                REQUIRE(idx <= 5*4*3);
+                CHECK(indices[idx].x == x);
+                CHECK(indices[idx].y == y);
+                CHECK(indices[idx].z == z);
+            }
+        }
+    }
+}
+
+TEST_CASE("n=4 objects long long", "n_to_one") {
+    Indices indices[5*4*3*2];
+    unsigned long long x;
+    unsigned long long y;
+    unsigned long long z;
+    unsigned long long i;
+    unsigned long long idx;
+
+    for(idx = 0; idx < 5*4*3*2; ++idx) {
+        one_to_four_l(idx, &x, &y, &z, &i, 5, 4, 3);
+        indices[idx].x = x;
+        indices[idx].y = y;
+        indices[idx].z = z;
+        indices[idx].i = i;
+    }
+
+    for(i = 0; i < 2; ++i) {
+        for(z = 0; z < 3; ++z) {
+            for(y = 0; y < 4; ++y) {
+                for(x = 0; x < 5; ++x) {
+                    idx = four_to_one_l(x, y, z, i, 5, 4, 3);
+                    REQUIRE(idx <= 5*4*3*2);
+                    CHECK(indices[idx].x == x);
+                    CHECK(indices[idx].y == y);
+                    CHECK(indices[idx].z == z);
+                    CHECK(indices[idx].i == i);
+                }
+            }
+        }
+    }
+}

third_party/Catch2

@@ -0,0 +1 @@
+Subproject commit 7727c15290ce2d289c1809d0eab3cceb88384ad6