百练+EK算法模版+网络流邻接表形式

来源：互联网发布：图像边缘检测算法代码编辑：程序博客网时间：2024/06/05 07:31

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//在于建图#include <iostream>#include <stdio.h>#include <stdlib.h>#include <string>#include <cstring>#include <string.h>#include <math.h>#include <algorithm>#include <queue>#include <vector>#include <map>#define LL long long#define inf 0x3f3f3f3f#define mod 1e9+7using namespace std;const int maxn=405;LL cap[maxn][maxn],flow[maxn][maxn],rest[maxn];int snode,tnode,pre[maxn],vis[maxn];bool BFS_Path(int m)//augmenting path{    memset(vis, 0, sizeof(vis));    queue<int>Q;    int u=0,v=0;    u=snode; pre[u]=u;    rest[u]=inf;vis[u]=1;    Q.push(u);    while (!Q.empty()) {        u=Q.front(); Q.pop();        for(v=0;v<=m;v++){            if(!vis[v]&&flow[u][v]<cap[u][v]){                pre[v]=u;vis[v]=1;                rest[v]=min(rest[u],cap[u][v]-flow[u][v]);                if(v==tnode) return true; // find augment path                Q.push(v);            }        }    }    return false;}int max_flow(int s, int t, int m){    snode=s;tnode=t;    int ans=0;    while (BFS_Path(m)) {        ans+=rest[t];        int v=t;        while (v!=s) {            int u=pre[v];            flow[u][v]+=rest[t];            flow[v][u]-=rest[t];            v=u;        }    }    return ans;}int main(){    int N=0,F=0,D=0;    int s=0,t=0,num1=0,num2=0,num=0;    scanf("%d %d %d",&N,&F,&D);    memset(cap, 0, sizeof(cap));    memset(flow, 0, sizeof(flow));    memset(pre, 0, sizeof(pre));    memset(rest, 0, sizeof(rest));    s=0; t=2*N+F+D+1;    for(int i=1;i<=F;i++) cap[s][i]=1;    for(int i=F+2*N+1;i<=F+2*N+D;i++) cap[i][t]=1;    for(int i=1;i<=N;i++) cap[F+2*i-1][F+2*i]=1;    for(int i=1;i<=N;i++){        scanf("%d %d",&num1,&num2);        while (num1--) {            scanf("%d",&num);            cap[num][F+2*i-1]=1;        }        while (num2--) {            scanf("%d",&num);            cap[F+2*i][F+2*N+num]=1;        }    }    printf("%d\n",max_flow(s,t,t));    return 0;}

#include <iostream>#include <stdio.h>#include <stdlib.h>#include <algorithm>#include <queue>#include <string.h>#include <vector>#define inf 0x3f3f3f3f#pragma comment(linker, "/STACK:102400000,102400000")using namespace std;const int maxn=20005;struct edge{    int from,to,cap,flow;    edge(int u, int v, int c, int f):from(u),to(v),cap(c),flow(f){};};vector<edge> ed;vector<int> G[maxn];int snode,tnode,pre[maxn],vis[maxn],rest[maxn];void init(int t){    for(int i=0;i<=t;i++) G[i].clear();    ed.clear();}void addEdge(int from, int to, int cap){    ed.push_back(edge(from, to, cap, 0));    ed.push_back(edge(to, from, 0, 0));    int num=ed.size();    G[from].push_back(num-2);    G[to].push_back(num-1);}bool BFS_Path(int m)///augmenting path{    memset(vis, 0, sizeof(vis));    queue<int>Q;    int u=0;    u=snode; pre[u]=u;    rest[u]=inf;vis[u]=1;    Q.push(u);    while (!Q.empty()) {        u=Q.front(); Q.pop();        for(int i=0;i<G[u].size();i++){            edge &e=ed[G[u][i]];            if(!vis[e.to]&&e.flow<e.cap){                pre[e.to]=G[u][i];vis[e.to]=1;                rest[e.to]=min(rest[u],e.cap-e.flow);                if(e.to==tnode) return true; /// find augment path                Q.push(e.to);            }        }    }    return false;///no augment path}int max_flow(int s, int t, int m){    snode=s;tnode=t;    int ans=0;    while (BFS_Path(m)) {        ans+=rest[t];        //cout<<ans<<endl;        /*int v=t;        while (v!=s) {            int u=pre[v];            ed[u].flow+=rest[t];            ed[v].flow-=rest[t];            v=u;        }        */        for(int e=t;e!=s;e=ed[pre[e]].from)        {            ed[pre[e]].flow+=rest[t];            ed[pre[e]^1].flow-=rest[t];        }    }    return ans;}int main(){    int N=0,M=0,A=0,B=0,a=0,b=0,w=0;    memset(pre, 0, sizeof(pre));    memset(rest, 0, sizeof(rest));    scanf("%d %d",&N,&M);    int s=0,t=N+1;    init(t);    for(int i=1;i<=N;i++){        scanf("%d %d",&A,&B);        addEdge(s, i, A);        addEdge(i, t, B);    }    for(int i=1;i<=M;i++){        scanf("%d %d %d",&a,&b,&w);        ed.push_back(edge(a, b, w, 0));        ed.push_back(edge(b, a, w, 0));        int num=ed.size();        G[a].push_back(num-2);        G[b].push_back(num-1);    }    printf("%d\n",max_flow(s,t,t));    return 0;}

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