NEU 1458 square fetch (cost stream of network Stream)

Address: neu 1458

The two squares on hangdian are not the same .. This can be repeated, but the sum can only be added once. The idea of creating a graph is coming soon. The same split point only requires another split edge. One of them costs 0, and the other is the value at that point. The traffic is limited to 1. Then the remaining two are similar to those on Hangzhou power. Because the array is opened several times lower than wa .. (I checked the array size before, but I thought it was not small yet... You are speechless ..)

The Code is as follows:

#include <iostream>#include <stdio.h>#include <string.h>#include <stdlib.h>#include <math.h>#include <ctype.h>#include <queue>#include <map>#include<algorithm>using namespace std;const int INF=0x3f3f3f3f;int head[21000], source, sink, cnt, mp[101][101], flow, cost, n;int vis[21000], d[21000], cur[21000];struct node{    int u, v, cap, cost, next;} edge[1000000];void add(int u, int v, int cap, int cost){    edge[cnt].v=v;    edge[cnt].cap=cap;    edge[cnt].cost=cost;    edge[cnt].next=head[u];    head[u]=cnt++;    edge[cnt].v=u;    edge[cnt].cap=0;    edge[cnt].cost=-cost;    edge[cnt].next=head[v];    head[v]=cnt++;}int spfa(){    int i, minflow=INF;    memset(d,INF,sizeof(d));    memset(vis,0,sizeof(vis));    cur[source]=-1;    d[source]=0;    queue<int>q;    q.push(source);    while(!q.empty())    {        int u=q.front();        q.pop();        vis[u]=0;        for(i=head[u]; i!=-1; i=edge[i].next)        {            int v=edge[i].v;            if(d[v]>d[u]+edge[i].cost&&edge[i].cap)            {                d[v]=d[u]+edge[i].cost;                minflow=min(minflow,edge[i].cap);                cur[v]=i;                if(!vis[v])                {                    vis[v]=1;                    q.push(v);                }            }        }    }    if(d[sink]==INF) return 0;    flow+=minflow;    cost-=minflow*d[sink];    //printf("%d %d\n",minflow,d[sink]);    for(i=cur[sink]; i!=-1; i=cur[edge[i^1].v])    {        edge[i].cap-=minflow;        edge[i^1].cap+=minflow;    }    return 1;}void mcmf(){    flow=cost=0;    while(spfa()) ;    printf("%d\n",cost);}int main(){    int i, j;    while(scanf("%d",&n)!=EOF)    {        for(i=1; i<=n; i++)        {            for(j=1; j<=n; j++)            {                scanf("%d",&mp[i][j]);            }        }        memset(head,-1,sizeof(head));        cnt=0;        source=0;        sink=2*n*n+1;        add(source,1,2,0);        add(2*n*n,sink,2,0);        for(i=1; i<=n; i++)        {            for(j=1; j<=n; j++)            {                add((i-1)*n+j,(i-1)*n+j+n*n,1,0);                add((i-1)*n+j,(i-1)*n+j+n*n,1,-mp[i][j]);                if(1+j<=n)                {                    add((i-1)*n+j+n*n,(i-1)*n+j+1,2,0);                }                if(i+1<=n)                {                    add((i-1)*n+j+n*n,i*n+j,2,0);                }            }        }        mcmf();    }    return 0;}