Data commit

Task/Longest-common-subsequence/C/longest-common-subsequence-1.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAX(a, b) (a > b ? a : b)
+
+int lcs (char *a, int n, char *b, int m, char **s) {
+    int i, j, k, t;
+    int *z = calloc((n + 1) * (m + 1), sizeof (int));
+    int **c = calloc((n + 1), sizeof (int *));
+    for (i = 0; i <= n; i++) {
+        c[i] = &z[i * (m + 1)];
+    }
+    for (i = 1; i <= n; i++) {
+        for (j = 1; j <= m; j++) {
+            if (a[i - 1] == b[j - 1]) {
+                c[i][j] = c[i - 1][j - 1] + 1;
+            }
+            else {
+                c[i][j] = MAX(c[i - 1][j], c[i][j - 1]);
+            }
+        }
+    }
+    t = c[n][m];
+    *s = malloc(t);
+    for (i = n, j = m, k = t - 1; k >= 0;) {
+        if (a[i - 1] == b[j - 1])
+            (*s)[k] = a[i - 1], i--, j--, k--;
+        else if (c[i][j - 1] > c[i - 1][j])
+            j--;
+        else
+            i--;
+    }
+    free(c);
+    free(z);
+    return t;
+}

Task/Longest-common-subsequence/C/longest-common-subsequence-2.c

@@ -0,0 +1,10 @@
+int main () {
+    char a[] = "thisisatest";
+    char b[] = "testing123testing";
+    int n = sizeof a - 1;
+    int m = sizeof b - 1;
+    char *s = NULL;
+    int t = lcs(a, n, b, m, &s);
+    printf("%.*s\n", t, s); // tsitest
+    return 0;
+}