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Cod sursa(job #134714)
#include<stdio.h>
long int sol,n,m,i,x[3670],y[3670],c[3670],cost[65][65],
k,j,ccc,pol[65],lin,col,cap[65][65],dist[65],pred[65],
viz[65],ok,e,cmin,flow,i8=100000000,fc,fl[65][65];
void citire();
long int find_path();
void act_flow();
void roy();
int main()
{ FILE *g;g=fopen("traseu.out","w");
citire();
while(find_path())
act_flow();
fprintf(g,"%ld\n",sol);
return 0;
}
void citire()
{
FILE *f;f=fopen("traseu.in","r");
fscanf(f,"%ld%ld",&n,&m);
for(i=1;i<=m;i++){fscanf(f,"%ld%ld%ld",&x[i],&y[i],&c[i]);cost[x[i]][y[i]]=c[i];sol+=c[i];pol[x[i]]++;pol[y[i]]--;}
roy();
for(i=1;i<=n;i++)if(pol[i]<0)cap[0][i]=-pol[i];
for(i=1;i<=n;i++)if(pol[i]>0)cap[i][n+1]=pol[i];
for(i=1;i<=n;i++)if(pol[i]<0)for(j=1;j<=n;j++)if(pol[j]>0){ cap[i][j]=i8;cost[j][i]=-cost[i][j];}
}
long int find_path()
{
for(i=0;i<=n+1;i++){ dist[i]=i8;pred[i]=0;viz[i]=0;}
pred[0]=-1;
ok=1;
while(ok)
{ ok=0;e=-1;cmin=i8;
for(i=0;i<=n+1;i++)if(dist[i]<cmin&&!viz[i]){cmin=dist[i];e=i;}
if(e==n+1) return 1;
if(e>-1)
{ viz[e]=1;
ok=1;
for(i=0;i<=n+1;i++)if(cap[e][i])if(!viz[i]&&dist[i]>dist[e]+cost[e][i]){dist[i]=dist[e]+cost[e][i];pred[i]=e;}
}
}
return 0;
}
void act_flow()
{
fc=i8;
for(k=n+1;pred[k]>=0;k=pred[k])
if(cap[pred[k]][k]<fc)
fc=cap[pred[k]][k];
for(k=n+1;pred[k]>=0;k=pred[k])
{ cap[pred[k]][k]-=fc;cap[k][pred[k]]+=fc;
fl[pred[k]][k]+=fc;fl[k][pred[k]]-=fc;
}
sol+=fc*dist[n];
}
void roy()
{ for(k=1;k<=n;k++)
for(i=1;i<=n;i++)
{ if(cost[i][k])
for(j=1;j<=n;j++)
{ if(cost[k][j])
if(!cost[i][j]||cost[i][j]>cost[i][k]+cost[k][j])
cost[i][j]=cost[i][k]+cost[k][j];
}
}
}