Algo-Trian

Algorithm/Graph/Bellman-Ford有负边的最短路径.cpp

@@ -0,0 +1,48 @@
+#include <iostream>
+#include <tuple>
+#include <vector>
+#include <climits>
+using namespace std;
+const int INF = INT_MAX >> 1;
+int main(){
+	int n, edge_num, start;
+	cin >> n >> edge_num >> start;
+	
+	//<2F><><EFBFBD><EFBFBD>Ҫadj, <20><>Ҫdp <20><> edges 
+	vector<tuple<int, int , int>> edges(edge_num);// p1, p2, w
+	vector<int> dp(n, INF);
+	dp[start] = 0;
+	
+	//<2F><><EFBFBD><EFBFBD>
+	for(int i = 0; i < edge_num; i++){
+		int a, b, w;
+		cin >> a >> b >> w;
+		edges[i] = {a, b, w};
+	} 
+	
+	//<2F>Ƚ<EFBFBD><C8BD><EFBFBD>n - 1<><31><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
+	for(int i = 0; i < n - 1; i++){
+		for(auto [p1, p2, w] : edges){
+			if(dp[p2] > dp[p1] + w){
+				dp[p2] = dp[p1] + w;
+			}
+		} 
+	}
+	
+	//<2F>Ƿ<EFBFBD><C7B7>и<EFBFBD><D0B8><EFBFBD> 
+	bool negcc = false;
+	for(auto [p1, p2, w] : edges){
+		if(dp[p2] > dp[p1] + w){
+			negcc = true;
+			break;
+		}
+	}
+	
+	if(negcc) cout << "Negative Circle Detected" << endl;
+	else{
+		for(auto x : dp){
+			cout << x << " ";
+		}
+	}
+	return 0;
+}