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| #include <iostream>
typedef unsigned int WORD ;
using namespace std ;
const int MaxN = 101 ;
struct List {
List (){} ;
List ( int _V , List * _next ) { V = _V ; next = _next ;}
List * next ;
int V ;
};
int e[MaxN];
int h[MaxN];
int f[MaxN][MaxN];
int c[MaxN][MaxN];
List *head[MaxN] , *current[MaxN] , *headL , *pre;
int n , m , s = 1, t , minH ;
void ConstructL(){
List *cur ;
List * t = new List (2 , NULL );
pre = headL = t ; cur = t ;
for (int i = 3 ; i < n ; i++ )
{
List *t = new List ( i , NULL) ;
cur->next = t ;
cur = cur->next ;
}
}
int min (int a , int b ){
return a<b ? a:b ;
}
void MoveToFront ( List *u ) {
if ( pre == u )return ;
pre->next = u->next ;
List * t = new List (u->V , headL ) ;
pre = headL = t ;
delete u ;
}
void Initilize_PreFlow () {
h[s] = n ;
for (int u = 1 ; u <= n ; u++ ){
if ( c[s][u] > 0 ){
f[s][u] = c[s][u] ;
f[u][s] = -c[s][u] ;
e[u] = c[s][u];
}
}
}
void Push (int u , int v ){
int d = min (e[u] , c[u][v]-f[u][v]);
f[u][v] = f[u][v] + d ;
f[v][u] = -f[u][v] ;
e[u] = e[u] - d ;
e[v] = e[v] + d ;
}
void Lift ( int u ) {
minH = 100000 ;
List *v = head[u];
while (v){
if (minH > h[v->V] && c[u][v->V]-f[u][v->V] > 0 )minH = h[v->V];
v = v->next ;
}
h[u] = ( minH +1 ) ;
}
void Discharge ( int u ){
while ( e[u] > 0 ){
List* v = current[u];
if ( current[u] == NULL ){
Lift ( u );
current[u] = head[u];
}
else if ( c[u][v->V]-f[u][v->V] > 0 && h[u] == h[v->V] + 1)
Push (u , v->V );
else current[u] = current[u]->next ;
}
}
void Lift_To_Front (){
Initilize_PreFlow() ;
ConstructL() ;
for (int i = 2 ; i < n ; i++ )
current[i] = head[i];
List *u = headL ;
while ( u != NULL ){
int old_height = h[u->V];
Discharge( u->V );
if ( h[u->V] > old_height ){
MoveToFront ( u );
u = headL;
}
pre = u ;
u = u->next ;
}
}
int main () {
setlocale (LC_ALL,"Russian");
cout<<"¬ведите количество вершин: ";
cin >> n;
cout<<"¬ведите количество ребер: ";
cin>>m;
cout<<"¬ведите ребра в формате: ребро1 ребро2 вес:"<<endl;
int a , b , cf ;
for (int i = 0 ; i < m ; i++ )
{
cin >> a >> b >> cf ;
c[a][b] = cf;
}
for (int i = 1 ; i <= n ; i++ ){
List *cur ;
int w = 0 ;
for (int j = 1 ; j <= n ; j ++ ){
if ( c[i][j] > 0 || c[j][i] > 0 ){
List * t = new List( j , NULL ) ;
if (!w){
head[i] = t ;
cur = t ;
w = 1 ;
}
else {
cur->next = t ;
cur = cur->next ;
}
}
}
}
Lift_To_Front ();
int sum = 0 ;
for (int i = 1 ; i <= n ; i++ )
sum += f[i][n];
cout <<"\nV(max)= "<< sum<<"\n\n";
return 0 ;
} |
(
