mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
113 lines
2.6 KiB
C++
113 lines
2.6 KiB
C++
#include<stdio.h>
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#include<string.h>
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#include<queue>
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#define N_node 2000
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#define N_eage 200090
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#define inf 1000000000
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using namespace std;
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typedef struct
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{
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int from ,to ,next ,cost ,flow;
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}STAR;
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STAR E[N_eage];
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int list[N_node] ,tot;
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int mer[N_eage];
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int s_x[N_node];
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void add(int a ,int b ,int c ,int d)
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{
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E[++tot].from = a;
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E[tot].to = b;
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E[tot].cost = c;
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E[tot].flow = d;
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E[tot].next = list[a];
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list[a] = tot;
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E[++tot].from = b;
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E[tot].to = a;
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E[tot].cost = -c;
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E[tot].flow = 0;
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E[tot].next = list[b];
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list[b] = tot;
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}
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bool spfa(int s ,int t ,int n)
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{
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for(int i = 0; i<= n ;i ++)
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s_x[i] = inf;
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s_x[s] = 0;
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bool mark[N_node] = {0};
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mark[s] = 1;
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queue<int>q;
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q.push(s);
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memset(mer ,255 ,sizeof(mer));
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while(!q.empty())
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{
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int xin ,tou;
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tou = q.front();
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q.pop();
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mark[tou] = 0;
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for(int k = list[tou] ;k ;k = E[k].next)
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{
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xin = E[k].to;
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if(s_x[xin] > s_x[tou] + E[k].cost && E[k].flow)
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{
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mer[xin] = k;
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s_x[xin] = s_x[tou] + E[k].cost;
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if(!mark[xin])
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{
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mark[xin] = 1;
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q.push(xin);
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}
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}
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}
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}
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return mer[t] != -1;
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}
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int M_C_flow(int s ,int t ,int n ,int p_num)
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{
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int minflow ,mincost = 0 ,maxflow = 0;
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while(spfa(s ,t ,n))
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{
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minflow = inf;
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for(int i = mer[t] ;i + 1 ;i = mer[E[i].from])
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{
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if(minflow > E[i].flow)
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minflow = E[i].flow;
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}
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for(int i = mer[t] ;i + 1 ;i = mer[E[i].from])
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{
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E[i].flow -= minflow;
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E[i^1].flow += minflow;
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mincost += E[i].cost * minflow;
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}
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maxflow += minflow;
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}
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if(maxflow != p_num) mincost = 1;
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return mincost;
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}
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int main ()
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{
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int i ,j ,n ,m ,num ,k ,a ,b ,c ,cc = 1;
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while(~scanf("%d %d %d" ,&n ,&m ,&k))
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{
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memset(list ,0 ,sizeof(list));
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tot = 1;
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for(i = 1 ;i <= k ;i ++)
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{
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scanf("%d %d %d" ,&a ,&b ,&c);
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a++ ,b ++;
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if(c < 0)continue;
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add(a ,b + n ,-c ,1);
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}
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int e = n + m + 1;
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for(i = 1 ;i <= n ;i ++)
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{
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add(0 ,i ,0 ,1);
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}
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for(i = 1 ;i <= m ;i ++)
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{
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add(i + n ,e ,0 ,1);
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}
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printf("Case %d: %d\n" ,cc++ ,-M_C_flow(0 ,e ,e ,n));
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}
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return 0;
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}
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