请用C++为我写一段代码,要求能实现以下功能:求出带权值的有向图里任意两点间的五条相对长度最短的路径
时间: 2024-03-25 20:39:07 浏览: 120
一个用C++写的求最短路径的代码
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好的,以下是一份可行的C++代码,使用了Dijkstra算法和堆优化,时间复杂度为O(mlogn):
```cpp
#include <iostream>
#include <vector>
#include <queue>
#include <cstring>
#include <algorithm>
using namespace std;
const int INF = 0x3f3f3f3f;
const int MAXN = 1005;
const int MAXM = 100005;
struct Edge {
int from, to, w;
Edge(int from, int to, int w) : from(from), to(to), w(w) {}
};
struct Node {
int id, dis;
bool operator<(const Node& rhs) const {
return dis > rhs.dis;
}
};
vector<Edge> edges;
vector<int> G[MAXN];
int n, m;
int d[MAXN][6]; // 任意两点间相对长度最短的五条路径
bool vis[MAXN];
void dijkstra(int s) {
memset(d, INF, sizeof(d));
memset(vis, 0, sizeof(vis));
priority_queue<Node> pq;
pq.push({s, 0});
d[s][0] = 0;
while (!pq.empty()) {
Node u = pq.top();
pq.pop();
if (vis[u.id]) continue;
vis[u.id] = true;
for (int i = 0; i < G[u.id].size(); i++) {
Edge& e = edges[G[u.id][i]];
for (int j = 0; j < 5; j++) {
int v = e.to, w = e.w;
if (d[u.id][j] == INF) break; // 之前的路径不存在,后面的也不存在
if (d[v][j+1] > d[u.id][j] + w) {
d[v][j+1] = d[u.id][j] + w;
pq.push({v, d[v][j+1]});
}
}
}
}
}
int main() {
// 输入n, m和边的信息
cin >> n >> m;
for (int i = 0; i < m; i++) {
int u, v, w;
cin >> u >> v >> w;
edges.push_back(Edge(u, v, w));
G[u].push_back(i);
}
// 求任意两点间相对长度最短的五条路径
for (int i = 1; i <= n; i++) {
dijkstra(i);
for (int j = 1; j <= n; j++) {
if (i == j) continue;
sort(d[j], d[j]+6);
cout << "从节点 " << i << " 到节点 " << j << " 的五条最短路径长度分别为: ";
for (int k = 1; k <= 5; k++) {
if (d[j][k] == INF) break;
cout << d[j][k] << " ";
}
cout << endl;
}
}
return 0;
}
```
希望这份代码能够帮助到你!
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