Cod sursa(job #2878905)

Utilizator AndreiPRPopescu Andrei AndreiPR Data 28 martie 2022 09:44:01
Problema Algola Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 2.83 kb
#include<fstream>
#include<algorithm>
#include<vector>
#include<queue>
#define INF 100
using namespace std;
ifstream f("algola.in");
ofstream g("algola.out");
struct elem
{
    int x,poz;
};
vector<elem>a[5002];
elem tata[5002];
int n,s,d,sol,r[100002],p[52],X[302],Y[302],C[302];
bool viz[5002];
queue<int>q;

inline bool bfs()
{
    int i,x,l;
    for(i=0;i<=d+n;i++)
        viz[i]=0,tata[i]={-1,0};
    q.push(s);
    viz[s]=1;
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        l=a[x].size();
        for(i=0;i<l;i++)
        if(viz[a[x][i].x]==0&&r[a[x][i].poz]>0)
        {
            viz[a[x][i].x]=1;
            tata[a[x][i].x].x=x;
            tata[a[x][i].x].poz=a[x][i].poz;
            q.push(a[x][i].x);
        }
    }
    return viz[d];
}

inline void flux_maxim()
{
    int i,j,flow,l=a[d].size();
    while(bfs()!=0)
    {
        for(i=0;i<l;i++)
        if((tata[a[d][i].x].x!=-1||a[d][i].x==s)&&r[a[d][i].poz^1]>0)
        {
            flow=r[a[d][i].poz^1];
            for(j=a[d][i].x;j!=s;j=tata[j].x)
            {
                flow=min(flow,r[tata[j].poz]);
                if(flow==0)
                    break;
            }
            if(flow!=0)
            {
                r[a[d][i].poz^1]-=flow;
                r[a[d][i].poz]+=flow;
                for(j=a[d][i].x;j!=s;j=tata[j].x)
                {
                    r[tata[j].poz]-=flow;
                    r[tata[j].poz^1]+=flow;
                }
                sol+=flow;
            }
        }
    }
}

int main()
{
    int m,i,k=0,all=0,t;
    f>>n>>m;
    for(i=1;i<=n;i++)
        f>>p[i],all+=p[i];
    for(i=1;i<=m;i++)
        f>>X[i]>>Y[i]>>C[i];
    s=0;
    for(i=1;i<=n;i++)
    if(p[i]!=0)
    {
        r[k]=p[i];
        a[s].push_back({i,k});
        k++;
        r[k]=0;
        a[i].push_back({s,k});
        k++;
    }
    for(t=0;t<=n+all;t++)
    {
        if(t!=0)
        {
            for(i=1;i<=n;i++)
            {
                r[k]=INF;
                a[(t-1)*n+i].push_back({t*n+i,k});
                k++;
                r[k]=0;
                a[t*n+i].push_back({(t-1)*n+i,k});
                k++;
            }
            for(i=1;i<=m;i++)
            {
                r[k]=C[i];
                a[(t-1)*n+X[i]].push_back({t*n+Y[i],k});
                k++;
                r[k]=0;
                a[t*n+Y[i]].push_back({(t-1)*n+X[i],k});
                k++;
                r[k]=C[i];
                a[(t-1)*n+Y[i]].push_back({t*n+X[i],k});
                k++;
                r[k]=0;
                a[t*n+X[i]].push_back({(t-1)*n+Y[i],k});
                k++;
            }
        }
        d=t*n+1;
        flux_maxim();
        if(sol==all)
            break;
    }
    g<<t;
    return 0;
}