HDU 4284Travel（状压DP）

  1 //#pragma comment(linker,"/STACK:102400000,102400000")
  2 #include <map>
  3 #include <set>
  4 #include <stack>
  5 #include <queue>
  6 #include <cmath>
  7 #include <ctime>
  8 #include <vector>
  9 #include <cstdio>
 10 #include <cctype>
 11 #include <cstring>
 12 #include <cstdlib>
 13 #include <iostream>
 14 #include <algorithm>
 15 using namespace std;
 16 #define INF 1e8
 17 #define inf (-((LL)1<<40))
 18 #define lson k<<1, L, mid
 19 #define rson k<<1|1, mid+1, R
 20 #define mem0(a) memset(a,0,sizeof(a))
 21 #define mem1(a) memset(a,-1,sizeof(a))
 22 #define mem(a, b) memset(a, b, sizeof(a))
 23 #define FOPENIN(IN) freopen(IN, "r", stdin)
 24 #define FOPENOUT(OUT) freopen(OUT, "w", stdout)
 25 template<class T> T CMP_MIN(T a, T b) { return a < b; }
 26 template<class T> T CMP_MAX(T a, T b) { return a > b; }
 27 template<class T> T MAX(T a, T b) { return a > b ? a : b; }
 28 template<class T> T MIN(T a, T b) { return a < b ? a : b; }
 29 template<class T> T GCD(T a, T b) { return b ? GCD(b, a%b) : a; }
 30 template<class T> T LCM(T a, T b) { return a / GCD(a,b) * b;    }
 31 
 32 //typedef __int64 LL;
 33 //typedef long long LL;
 34 const int MAXN = 600;
 35 const int MAXM = 100005;
 36 const double eps = 1e-13;
 37 //const LL MOD = 1000000007;
 38 
 39 int T, N, M, H, Money;
 40 int dis[MAXN][MAXN], add[MAXN], cost[MAXN];
 41 int citys[20], dp[1<<18][18];
 42 
 43 void init()
 44 {
 45     int u, v, w, c, a;
 46      mem0(add); mem0(cost);mem1(dp);
 47     scanf("%d %d %d", &N, &M, &Money);
 48     for(int i =0 ; i <= N ;i ++ )
 49     {
 50         dis[i][i] = 0;
 51         for(int j = 0; j <= N ; j ++ )
 52             if(i != j) dis[i][j] = INF;
 53     }
 54     for(int i = 0; i < M; i ++ )
 55     {
 56         scanf("%d %d %d", &u, &v, &w);
 57         dis[u][v] = dis[v][u] = MIN(dis[u][v], w);
 58     }
 59     scanf("%d", &H);
 60     for(int i = 1; i <= H; i ++ )
 61     {
 62         scanf("%d %d %d", &u, &a, &c);
 63         citys[i] = u;
 64         add[i] = a;
 65         cost[i] = c;
 66     }
 67 }
 68 
 69 void floyd()
 70 {
 71     for(int k=1;k<=N;k++)
 72     for(int i=1;i<=N;i++)
 73     for(int j=1;j<=N;j++)
 74     {
 75         dis[i][j] = MIN(dis[i][j], dis[i][k] + dis[k][j]);
 76     }
 77 }
 78 
 79 int main()
 80 {
 81     //FOPENIN("in.txt");
 82     while(~scanf("%d", &T)) while(T--)
 83     {
 84         init();
 85         floyd();
 86         int ans = -INF; H += 1;
 87         citys[0] = 1; cost[0] = add[0] = 0;
 88         dp[1][0] = Money;
 89         for(int now = 1; now < (1<<H); now ++ )
 90         {
 91             for(int u = 0; u < H; u ++ ) if(dp[now][u] != -1)
 92             {
 93                 for(int v = 1; v < H; v ++ ) if( (now & (1<<v)) == 0 )
 94                 {
 95                     int next = now | (1<<v);
 96                     if(dp[now][u] >= dis[citys[u]][citys[v]] + cost[v] )
 97                     {
 98                         dp[next][v] = MAX(dp[now | (1<<v)][v], dp[now][u] - dis[citys[u]][citys[v]] - cost[v] + add[v]);
 99                     }
100                     if(next == (1<<H) - 1)
101                     {
102                         ans = MAX(ans, dp[next][v]);
103                     }
104                 }
105             }
106         }
107        //printf("%d\n", ans);
108         printf("%s\n", ans >= 0 ? "YES" : "NO");
109     }
110     return 0;
111 }