Initial data commit

Task/Matrix-chain-multiplication/C/matrix-chain-multiplication.c

@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <limits.h>
+#include <stdlib.h>
+
+int **m;
+int **s;
+
+void optimal_matrix_chain_order(int *dims, int n) {
+    int len, i, j, k, temp, cost;
+    n--;
+    m = (int **)malloc(n * sizeof(int *));
+    for (i = 0; i < n; ++i) {
+        m[i] = (int *)calloc(n, sizeof(int));
+    }
+
+    s = (int **)malloc(n * sizeof(int *));
+    for (i = 0; i < n; ++i) {
+        s[i] = (int *)calloc(n, sizeof(int));
+    }
+
+    for (len = 1; len < n; ++len) {
+        for (i = 0; i < n - len; ++i) {
+            j = i + len;
+            m[i][j] = INT_MAX;
+            for (k = i; k < j; ++k) {
+                temp = dims[i] * dims[k + 1] * dims[j + 1];
+                cost = m[i][k] + m[k + 1][j] + temp;
+                if (cost < m[i][j]) {
+                    m[i][j] = cost;
+                    s[i][j] = k;
+                }
+            }
+        }
+    }
+}
+
+void print_optimal_chain_order(int i, int j) {
+    if (i == j)
+        printf("%c", i + 65);
+    else {
+        printf("(");
+        print_optimal_chain_order(i, s[i][j]);
+        print_optimal_chain_order(s[i][j] + 1, j);
+        printf(")");
+    }
+}
+
+int main() {
+    int i, j, n;
+    int a1[4]  = {5, 6, 3, 1};
+    int a2[13] = {1, 5, 25, 30, 100, 70, 2, 1, 100, 250, 1, 1000, 2};
+    int a3[12] = {1000, 1, 500, 12, 1, 700, 2500, 3, 2, 5, 14, 10};
+    int *dims_list[3] = {a1, a2, a3};
+    int sizes[3] = {4, 13, 12};
+    for (i = 0; i < 3; ++i) {
+        printf("Dims  : [");
+        n = sizes[i];
+        for (j = 0; j < n; ++j) {
+            printf("%d", dims_list[i][j]);
+            if (j < n - 1) printf(", "); else printf("]\n");
+        }
+        optimal_matrix_chain_order(dims_list[i], n);
+        printf("Order : ");
+        print_optimal_chain_order(0, n - 2);
+        printf("\nCost  : %d\n\n", m[0][n - 2]);
+        for (j = 0; j <= n - 2; ++j) free(m[j]);
+        free(m);
+        for (j = 0; j <= n - 2; ++j) free(s[j]);
+        free(s);
+    }
+    return 0;
+}