示例1:
输入
5 4 2
1 2 1
2 3 1
3 4 1
4 5 1
1 5
2 4
输出
5
示例2:
输入
6 10 3
1 1 6
5 6 9
3 5 8
1 4 1
2 4 7
6 6 10
1 4 2
6 5 10
3 5 2
3 1 9
1 5
2 5
4 3
输出
28
示例3
输入
6 10 3
1 1 3
3 1 1
6 2 3
1 6 10
4 1 1
3 1 2
5 6 9
5 4 10
6 3 4
3 4 4
3 5
3 6
6 5
输出
16
代码:
#include <bits/stdc++.h>
using namespace std;
const int maxn = 300 + 5;
int n, m, t;
long long dis[maxn][maxn];
long long f[maxn * 2][maxn];
int main(){
int i, j, k;
int x, y;
long long w;
memset(dis, 0x3f, sizeof(dis));
memset(f, 0x3f, sizeof(f));
scanf("%d%d%d", &n, &m, &t);
for(i=1;i<=n;i++) dis[i][i] = 0;
for(i=1;i<=m;i++){
scanf("%d%d%lld", &x, &y, &w);
dis[x][y] = min(dis[x][y], w);
dis[y][x] = min(dis[y][x], w);
}
for(k=1;k<=n;k++){
for(i=1;i<=n;i++){
for(j=1;j<=n;j++){
dis[i][j] = min(dis[i][j], dis[i][k] + dis[k][j]);
}
}
}
f[0][0] = 0;
int a = 1, b;
for(i=1;i<=t*2;i++){
scanf("%d", &b);
f[i][0] = min(f[i][0], f[i - 1][0] + dis[a][b]);
for(j=1;j<=n;j++){
f[i][j] = min(f[i][j], f[i - 1][0] + dis[a][j] + dis[j][b]);
}
for(j=1;j<=n;j++){
f[i][j] = min(f[i][j], min(f[i - 1][j] + dis[j][b], f[i - 1][j] + dis[a][b]));
f[i][a] = min(f[i][a], min(f[i - 1][j] + dis[j][b], f[i - 1][j] + dis[a][b]));
for(k=1;k<=n;k++){
f[i][k] = min(f[i][k], min(f[i - 1][j] + dis[j][k] + dis[k][b], f[i - 1][j] + dis[a][k] + dis[k][b]));
}
}
a = b;
}
long long ans = 0x3f3f3f3f3f3f3f3f;
for(i=0;i<=n;i++){
ans = min(ans, f[2 * t][i]);
}
printf("%lld\n", ans);
return 0;
}