EPA: Floyd Warshall

floyd_warshall.c

@@ -0,0 +1,44 @@
+#include <stdio.h>
+
+#define N 3
+
+typedef int Mat[N*N];
+
+void matiter(Mat C, int (*reduce)(int old, int ik, int kj)) {
+    for(unsigned int k = 0; k < N; k++) {
+        for(unsigned int i = 0; i < N; i++) {
+            for(unsigned int j = 0; j < N; j++) {
+                C[i*N+j] = reduce(C[i*N+j], C[i*N+k], C[k*N+j]);
+            }
+        }
+    }
+}
+
+int floyd(int old, int ik, int kj) {
+    int new = ik + kj;
+    return ( old < new ? old : new );
+}
+
+int warshall(int old, int ik, int kj) {
+    return (old ? old : ik && kj);
+}
+
+int main( int argc, char *argv[] ) {
+	Mat C =
+    {
+        0 , 0 , 0 ,
+        1 , 0 , 0 ,
+        0 , 1 , 0
+    };
+
+    matiter(C, *warshall);
+
+    for(unsigned int i = 0; i < N; i++) {
+        for(unsigned int j = 0; j < N; j++) {
+            printf("%5d ", C[i*N+j]);
+        }
+        printf("\n");
+    }
+
+	return 0;
+}