I am back: Internet bandwidth

Author: hackerkid

Diff for: 1153-Internet-Bandwidth.cpp

@@ -0,0 +1,129 @@
+#include <iostream>
+#include <stdio.h>
+#include <string.h>
+#include <vector>
+#include <stack>
+#include <limits.h>
+using namespace std;
+
+int s;
+int t;
+int n;
+
+vector < vector < pair <int, int> > > g;
+int a[110][110];
+int parent[110];
+
+int dfs()
+{
+
+	int vis[110];
+	int top;
+	int x;
+	
+	memset(vis, 0, sizeof vis);
+
+	stack <int> q;
+	q.push(s);
+	vis[s] = 1;
+
+	
+	while(!q.empty()) {
+		top = q.top();
+		q.pop();
+		for (int i = 0; i < g[top].size(); i++) {
+			x = g[top][i].first;
+			if(a[top][x] > 0 and vis[x] == 0) {
+				q.push(x);
+				vis[x] = 1;
+				parent[x] = top;
+			}
+
+		}
+
+
+	}
+	return vis[t] == 1;
+
+
+
+}
+
+
+int main()
+{
+
+	int x;
+	int y;
+	int w;
+	int CS;
+	int flow;
+	int k;
+	int c;
+	int p;
+	int ans;
+
+
+
+
+	scanf("%d", &CS);
+
+	for (int cs = 1; cs <= CS; cs++) {
+		scanf("%d", &n);
+		scanf("%d", &s);
+		scanf("%d", &t);
+		scanf("%d", &c);
+		
+		memset(a, 0, sizeof(a));
+		vector < vector < pair <int, int> > > tg(n+2);
+
+		swap(tg, g);
+		ans = 0;
+
+		for (int i = 0; i < c; i++) {
+			scanf("%d", &x);
+			scanf("%d", &y);
+			scanf("%d", &w);
+
+			a[x][y] += w;
+			a[y][x] += w;
+			g[x].push_back(make_pair(y, w));
+			g[y].push_back(make_pair(x, w));
+		}
+
+
+		while(dfs()) {
+			k = t;
+
+			flow = INT_MAX;
+			
+			while(k != s) {
+				p = parent[k];
+				flow = min(flow, a[k][p]);
+				k = parent[k];
+
+				
+			}
+			
+			
+			k = t;
+
+
+			while(k != s) {
+				p = parent[k];
+				a[k][p] -= flow;
+				a[p][k] -= flow;
+				k = parent[k];
+			}
+
+			ans += flow;
+		}
+
+		printf("Case %d: %d\n", cs, ans); 
+	}
+
+
+}
+
+
+