版权声明:本文为博主原创文章,转载请附上源地址。 https://blog.csdn.net/Ema1997/article/details/79700475
反思:巧妙的构图方式
再加上点与点之间的路径,最后再SPFA跑一下就可以了
#include <iostream>
#include <queue>
#include <cstdio>
#include <map>
#include <cstring>
#include <stack>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
const int INF = 0x3f3f3f3f;
const int maxn = 300005;
const int maxm = 600010;
struct Edge
{
int v, w, next;
Edge(){}
Edge(int vv, int ww, int nn) {
v = vv;
w = ww;
next = nn;
}
};
int head[maxn];
Edge e[maxm];
int dis[maxn];
int vis[maxn];
int flag[maxn];
int Level[maxn];
int m, n;
int cnt;
void Init()
{
cnt = 1;
memset (head, -1, sizeof(head));
memset (vis, 0, sizeof(vis));
memset (dis, 0x3f, sizeof(dis));
memset (Level, 0, sizeof(Level));
memset (flag, 0, sizeof(flag));
}
void Add(int u, int v, int w)
{
e[cnt] = Edge(v, w, head[u]);
head[u] = cnt++;
}
int SPFA(int u, int v)
{
queue<int> q;
q.push(u);
vis[u] = 1;
dis[u] = 0;
while (!q.empty()) {
int t = q.front();
q.pop();
vis[t] = 0;
for (int i = head[t]; i != -1; i = e[i].next) {
int tmp = e[i].v;
if (dis[t] + e[i].w < dis[tmp]) {
dis[tmp] = dis[t] + e[i].w;
if (vis[tmp] == 0) {
q.push(tmp);
vis[tmp] = 1;
}
}
}
}
return dis[v];
}
int main()
{
#ifndef ONLINE_JUDGE
freopen("in.txt", "r", stdin);
//freopen("out.txt", "w", stdout);
#endif // ONLINE_JUDGE
int t;
scanf ("%d", &t);
for (int kase = 1; kase <= t; kase++) {
int c;
scanf ("%d%d%d", &n, &m, &c);
Init ();
for (int i = 1; i <= n; i++) {
int l;
scanf ("%d", &l);
Level[i] = l;
flag[l] = 1;
}
for (int i = 1; i < n; i++) {
if (flag[i] && flag[i + 1]) {
Add (n + i, n + i + 1, c);
Add (n + i + 1, n + i, c);
}
}
for (int i = 1; i <= n; i++) {
int l = Level[i];
Add (n + l, i, 0);
if (l - 1 >= 1 && flag[l - 1]) {
Add (i, n + l - 1, c);
}
if (l + 1 <= n && flag[l + 1]) {
Add (i, n + l + 1, c);
}
}
for (int i = 0; i < m; i++) {
int u, v, w;
scanf ("%d%d%d", &u, &v, &w);
Add (u, v, w);
Add (v, u, w);
}
int path = SPFA (1, n);
if (path == INF) {
path = -1;
}
printf ("Case #%d: %d\n", kase, path);
}
return 0;
}