Merge pull request #664 from madihamallick/master

Added Floyed- Warshall Algorithm in C

Author: smv1999

Dynamic Programming/Floyed- Warshall.c

@@ -0,0 +1,89 @@
+/* Write a program to implement all pair of Shortest path for
+a given graph (Floyed- Warshall Algorithm) using
+Dynamic Programing approach. 
+
+            1  2  3  4  5
+        __  _  _  _  _  _
+        |
+    1   |   0  3  8  X  -4
+    2   |   X  0  X  1   7
+    3   |   X  4  0  X   X      ==> D[0]
+    4   |   2  X  -5 0   X
+    5   |   X  X  X  6   0
+
+
+            1  2  3  4  5
+        __  _  _  _  _  _
+        |
+    1   |   X  1  1  X   1
+    2   |   X  X  X  2   2
+    3   |   X  3  X  3   X      ==> pi[0]
+    4   |   X  X  4  X   X
+    5   |   X  X  X  5   X
+
+*/
+
+#include<stdio.h>
+#define infinity 1000000
+int D[100][100],PI[100][100],i,j,n,k;
+int main(){
+	printf("Enter no. of nodes:	");
+	scanf("%d",&n);
+	for(i=1;i<=n;i++){
+		for(j=1;j<=n;j++){
+			if (i==j){
+				D[i][j] = 0;
+			}
+			if (i!=j){			
+				printf("Enter cost of D[%d][%d]	", i,j);
+				scanf("%d", &D[i][j]);
+			}
+		}
+		printf("\n");
+	}
+	for(i=1;i<=n;i++){
+		for(j=1;j<=n;j++){
+			printf("Enter value of PI[%d][%d]	", i,j);
+			scanf("%d", &PI[i][j]);	
+		}
+		printf("\n");
+	}
+	printf("\n\nMatrix D\n\n");
+	for(i=1;i<=n;i++){
+		for(j=1;j<=n;j++){
+			printf("%d	",D[i][j]);
+		}
+		printf("\n");
+	}
+	printf("\n\nMatrix PI\n\n");
+	for(i=1;i<=n;i++){
+		for(j=1;j<=n;j++){
+			printf("%d	",PI[i][j]);
+		}
+		printf("\n");
+	}
+	for(k=1;k<=n;k++){
+		for(i=1;i<=n;i++){
+			for(j=1;j<=n;j++){
+				if(D[i][j] > (D[i][k] + D[k][j])){
+					D[i][j] = (D[i][k] + D[k][j]);
+					PI[i][j] = PI[k][j];
+				}
+			}
+		}
+	}
+	printf("\n\nFinal D Matrix\n\n");
+	for(i=1;i<=n;i++){
+		for(j=1;j<=n;j++){
+			printf("%d	",D[i][j]);
+		}
+		printf("\n");
+	}
+	printf("\n\nFinal PI Matrix\n\n");
+	for(i=1;i<=n;i++){
+		for(j=1;j<=n;j++){
+			printf("%d	",PI[i][j]);
+		}
+		printf("\n");
+	}
+}