Implemented Warshall Algorithm In C++

c++/graph/warshall.cpp

@@ -0,0 +1,84 @@
+#include <iostream>
+#include <climits>
+#include <iomanip>
+using namespace std;
+#define N 4
+#define M INT_MAX
+void printpath(int path[][N], int v, int u)
+{
+    if (path[v][u] == v)
+        return;
+
+    printpath(path, v, path[v][u]);
+    cout << path[v][u] << " ";
+}
+void solution(int cost[N][N], int path[N][N])
+{
+    for (int v = 0; v < N; v++)
+    {
+        for (int u = 0; u < N; u++)
+        {
+            if (u != v && path[v][u] != -1)
+            {
+                cout << "Shortest Path from " << v << " -> " << u << " is ("
+                     << v << " ";
+                printpath(path, v, u);
+                cout << u << ")" << endl;
+            }
+        }
+    }
+}
+
+void WarshallAlgo(int adjMatrix[][N])
+{
+    int cost[N][N], path[N][N];
+    for (int v = 0; v < N; v++)
+    {
+        for (int u = 0; u < N; u++)
+        {
+            cost[v][u] = adjMatrix[v][u];
+
+            if (v == u)
+                path[v][u] = 0;
+            else if (cost[v][u] != INT_MAX)
+                path[v][u] = v;
+            else
+                path[v][u] = -1;
+        }
+    }
+
+    for (int k = 0; k < N; k++)
+    {
+        for (int v = 0; v < N; v++)
+        {
+            for (int u = 0; u < N; u++)
+            {
+                if (cost[v][k] != INT_MAX && cost[k][u] != INT_MAX && cost[v][k] + cost[k][u] < cost[v][u])
+                {
+                    cost[v][u] = cost[v][k] + cost[k][u];
+                    path[v][u] = path[k][u];
+                }
+            }
+
+            if (cost[v][v] < 0)
+            {
+                cout << "Negative Weight Cycle Found!!";
+                return;
+            }
+        }
+    }
+    solution(cost, path);
+}
+
+int main()
+{
+    int adjMatrix[N][N] =
+        {
+            {0, M, -2, M},
+            {4, 0, 3, M},
+            {M, M, 0, 2},
+            {M, -1, M, 0}};
+    WarshallAlgo(adjMatrix);
+
+    return 0;
+}