先用floyd预处理出全源最短路,然后状压DP就可以了。。。
#include <iostream> #include <queue> #include <stack> #include <map> #include <set> #include <bitset> #include <cstdio> #include <algorithm> #include <cstring> #include <climits> #include <cstdlib> #include <cmath> #include <time.h> #define maxn 105 #define maxm 10005 #define eps 1e-7 #define mod 1000000007 #define INF 0x3f3f3f3f #define PI (acos(-1.0)) #define lowbit(x) (x&(-x)) #define mp make_pair #define ls o<<1 #define rs o<<1 | 1 #define lson o<<1, L, mid #define rson o<<1 | 1, mid+1, R #define pii pair<int, int> #pragma comment(linker, "/STACK:16777216") typedef long long LL; typedef unsigned long long ULL; //typedef int LL; using namespace std; LL qpow(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base;base=base*base;b/=2;}return res;} LL powmod(LL a, LL b){LL res=1,base=a;while(b){if(b%2)res=res*base%mod;base=base*base%mod;b/=2;}return res;} // head int dp[16][1 << 16]; int g[maxn][maxn]; int a[maxn]; int c[maxn]; int p[maxn]; int d[maxn]; int n, m, o, money; void init() { memset(g, INF, sizeof g); } void read() { int u, v, cc; scanf("%d%d%d", &n, &m, &money); while(m--) { scanf("%d%d%d", &u, &v, &cc); g[u][v] = min(g[u][v], cc); g[v][u] = min(g[v][u], cc); } for(int i = 0; i <= n; i++) g[i][i] = 0; scanf("%d", &m); for(int i = 0; i < m; i++) { scanf("%d%d%d", &a[i], &c[i], &d[i]); p[i] = 1 << i; } o = 1 << m; } void work() { for(int k = 1; k <= n; k++) for(int i = 1; i <= n; i++) for(int j = 1; j <= n; j++) g[i][j] = min(g[i][j], g[i][k] + g[k][j]); for(int i = 0; i < m; i++) for(int j = 0; j < o; j++) dp[i][j] = -INF; for(int i = 0; i < m; i++) if(money - g[1][a[i]] - d[i] >= 0) dp[i][p[i]] = max(dp[i][p[i]], money - g[1][a[i]] - d[i] + c[i]); for(int i = 0; i < o; i++) for(int j = 0; j < m; j++) if(dp[j][i] >= 0) for(int k = 0; k < m; k++) { if(i & p[k]) continue; if(dp[j][i] - d[k] - g[a[j]][a[k]] >= 0) dp[k][i | p[k]] = max(dp[k][i | p[k]], dp[j][i] - d[k] - g[a[j]][a[k]] + c[k]); } int ans = -INF; for(int i = 0; i < m; i++) ans = max(ans, dp[i][o - 1] - g[a[i]][1]); if(ans >= 0) printf("YES\n"); else printf("NO\n"); } int main() { int _; scanf("%d", &_); while(_--) { init(); read(); work(); } return 0; }