【HDOJ】2389 Rain on your Parade

读题显然是二分图匹配，看成guest与umbrella的匹配。匈牙利果断TLE了，其实时间卡的相当紧。HK过的，750ms。

 /* 2389 */
 #include <iostream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 using namespace std;

 typedef struct {
     int v, next;
 } Edge_t;

 const int maxn = ;

 Edge_t E[maxn*maxn];
 int head[maxn], L;
 int dx[maxn], dy[maxn];
 int xpre[maxn], ypre[maxn];
 int gx[maxn], gy[maxn], gs[maxn];
 bool visit[maxn];
 int rt, n, m;
 int ans, dis;

 void init() {
     L = ;
     memset(head, -, sizeof(head));
     memset(xpre, -, sizeof(xpre));
     memset(ypre, -, sizeof(ypre));
 }

 void addEdge(int u, int v) {
     E[L].v = v;
     E[L].next = head[u];
     head[u] = L++;
 }

 bool bfs() {
     int i, j, k;
     int u, v;
     queue<int> Q;

     memset(dx, -, sizeof(dx));
     memset(dy, -, sizeof(dy));
     dis = INT_MAX;

     for (i=; i<m; ++i) {
         if (xpre[i] == -) {
             Q.push(i);
             dx[i] = ;
         }
     }

     while (!Q.empty()) {
         u = Q.front();
         Q.pop();
         if (dx[u] > dis)
             break;
         for (i=head[u]; i!=-; i=E[i].next) {
             v = E[i].v;
             if (dy[v] == -) {
                 dy[v] = dx[u] + ;
                 if (ypre[v] == -) {
                     dis = dy[v];
                 } else {
                     dx[ypre[v]] = dy[v] + ;
                     Q.push(ypre[v]);
                 }
             }
         }
     }

     return dis!=INT_MAX;
 }

 int dfs(int u) {
     int i, v;
     // Edge_t e;

     for (i=head[u]; i!=-; i=E[i].next) {
         v = E[i].v;
         if (!visit[v] && dy[v]==dx[u]+) {
             visit[v] = true;
             if (ypre[v]!=- && dy[v]==dis)
                 continue;
             if (ypre[v]==- || dfs(ypre[v])) {
                 xpre[u] = v;
                 ypre[v] = u;
                 return ;
             }
         }
     }

     return ;
 }

 int HK() {
     int ret = ;

     while (bfs()) {
         memset(visit, false, sizeof(visit));
         for (int i=; i<m; ++i)
             if (xpre[i] == -)
                 ret += dfs(i);
     }
     return ret;
 }

 int main() {
     int i, j, k;
     int t, tt;
     int x, y;

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     scanf("%d", &tt);
     for (t=; t<=tt; ++t) {
         scanf("%d", &rt);
         scanf("%d", &m);
         init();
         for (i=; i<m; ++i)
             scanf("%d %d %d", &gx[i], &gy[i], &gs[i]);
         scanf("%d", &n);
         for (i=; i<n; ++i) {
             scanf("%d %d", &x, &y);
             for (j=; j<m; ++j) {
                 dis = gs[i] * rt;
                 if ((x-gx[j])*(x-gx[j])+(y-gy[j])*(y-gy[j]) <= dis*dis)
                     addEdge(j, i);
             }
         }
         ans = HK();
         printf("Scenario #%d:\n%d\n\n", t, ans);
     }

     #ifndef ONLINE_JUDGE
         printf("%d\n", (int)clock());
     #endif

     return ;
 }