hdu 3572 Task Schedule【 最大流 】

  1 #include<cstdio>
  2 #include<cstring>
  3 #include<iostream>
  4 #include<algorithm>
  5 #include<queue>
  6 using namespace std;
  7 
  8 const int maxn = 50005;
  9 const int INF = (1 << 30) - 1;
 10 
 11 struct Edge{
 12     int v,next,c;
 13 }e[10*maxn];
 14 
 15 int st,ed,lev[maxn],first[maxn],now[maxn],ecnt;
 16 int n,m;
 17 
 18 void init(){
 19     memset(first,-1,sizeof(first));
 20     ecnt = 0;
 21 }
 22 
 23 void addedges(int u,int v,int c){
 24     e[ecnt].next = first[u];
 25     e[ecnt].v = v;
 26     e[ecnt].c = c;
 27     first[u] = ecnt++;
 28     
 29     e[ecnt].next = first[v];
 30     e[ecnt].v = u;
 31     e[ecnt].c = 0;
 32     first[v] = ecnt++;
 33 }
 34 
 35 bool bfs(){
 36     queue<int> q;
 37     while(!q.empty()) q.pop();
 38     q.push(st);
 39     memset(lev,-1,sizeof(lev));
 40     lev[st] = 0;
 41     while(!q.empty()){
 42         int x = q.front();q.pop();
 43         for(int i = first[x];~i;i = e[i].next){
 44             int v = e[i].v;
 45             if(lev[v] < 0 && e[i].c > 0){
 46                 lev[v] = lev[x] + 1;
 47                 q.push(v);
 48             }
 49         }
 50     }
 51     return lev[ed] != -1;
 52 }
 53 
 54 int dfs(int p,int minf){
 55     if(p == ed || minf == 0) return minf;
 56     for(int &i = now[p];~i;i = e[i].next){
 57         int v = e[i].v;
 58         if(lev[v] == lev[p] + 1 && e[i].c > 0){
 59             int d = dfs(v,min(e[i].c,minf));
 60             if(d > 0){
 61                 e[i].c -= d;
 62                 e[i^1].c += d;
 63                 return d;
 64             }
 65         }
 66     }
 67     return 0;
 68 }
 69 
 70 int dinic(){
 71     int max_flow = 0,p1;
 72     while(bfs()){
 73         memcpy(now,first,sizeof(first));
 74         while((p1 = dfs(st,INF)) > 0)
 75         max_flow += p1;
 76     }
 77     return max_flow;
 78 }
 79 
 80 int main(){
 81     int T;
 82     int kase = 0;
 83     scanf("%d",&T);
 84     while(T--){        
 85         scanf("%d %d",&n,&m);
 86         init();
 87         st = 0;
 88         int maxx = -1;
 89         int sum = 0;
 90         for(int i = 1;i <= n;i++){
 91             int p,s,e;
 92             scanf("%d %d %d",&p,&s,&e);sum+=p;
 93             maxx = max(maxx,e);
 94             addedges(st,i,p);
 95             for(int j = s;j <= e;j++) addedges(i,j+n,1);
 96         }
 97         
 98         ed = n + maxx + 1;
 99         for(int j = 1;j <= maxx;j++) addedges(j+n,ed,m);
100         
101         int ans = dinic();
102         printf("Case %d: ",++kase);
103         if(ans == sum) puts("Yes");
104         else puts("No");
105         puts("");
106     }
107     return 0;
108 }