Mai intai trebuie sa te autentifici.
Cod sursa(job #355963)
Utilizator | Data | 12 octombrie 2009 20:27:59 | |
---|---|---|---|
Problema | Flux maxim | Scor | 70 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 1.68 kb |
#include <algorithm>
#include <vector>
using namespace std;
#define DIM ( 1<<10 )
#define INF ( 1<<30 )
#define pb push_back
#define sz size()
int n, m, cd[ DIM ], tat[ DIM ], viz[ DIM ], cst[ DIM ][ DIM ];
vector<int> vec[ DIM ];
void init_viz() {
int i;
for( i = 1; i <= n; ++i )
viz[ i ] = 0;
}
int bf() {
int st, dr, aux, nod;
unsigned int i;
init_viz();
cd[ 0 ] = 1;
viz[ 1 ] = 1;
for( st = dr = 0; st <= dr; ++st ) {
nod = cd[ st ];
for( i = 0; i < vec[ nod ].sz; ++i ) {
aux = vec[ nod ][ i ];
if( cst[ nod ][ aux ] > 0 && !viz[ aux ] ) {
viz[ aux ] = 1;
cd[ ++dr ] = aux;
tat[ aux ] = nod;
if( aux == n )
return 1;
}
}
}
return 0;
}
void read() {
int i, x0, y0, flx0;
scanf( "%d %d", &n, &m );
for( i = 0; i < m; ++i ) {
scanf( "%d %d %d", &x0, &y0, &flx0 );
vec[ x0 ].pb( y0 );
vec[ y0 ].pb( x0 );
cst[ x0 ][ y0 ] = flx0;
}
}
void solve() {
int flx, nod, fmin;
for( flx = 0; bf(); flx += fmin ) {
fmin = INF;
for( nod = n; nod != 1; nod = tat[ nod ] )
fmin = min( fmin, cst[ tat[ nod ] ][ nod ] );
for( nod = n; nod != 1; nod = tat[ nod ] ) {
cst[ tat[ nod ] ][ nod ] -= fmin;
cst[ nod ][ tat[ nod ] ] += fmin;
}
}
printf( "%d", flx );
}
int main() {
freopen( "maxflow.in", "r", stdin );
freopen( "maxflow.out", "w", stdout );
read();
solve();
return 0;
}