将行列分开来考虑
对于每一组交换,若对应点同色那么这组交换是没有意义的。我们只考虑两组交换是不同色的
建图
1、超级源连向所有的行和列,上界=下界=原本处在这一行的点数,费用为0;
2、对于每组交换i,j,若i为黑色,那么点i连向j,上界为1下界为0,费用为1;
3、所有的行和列连向超级汇,上界和下界为读入的限制,费用为0;
可行流判断是否有解,若有解则最小费用即答案
#include
#include
#include
#include
#define P 55
#define N 2050
#define INF (1<<30)
using namespace std;
int n,m,S,T,ss,tt,cnt=1,tot=0;
int head[N],d[N],p[N],qlc[P],qrc[P],qlr[P],qrr[P];
int map[P][P],sc[P],sr[P],r[P],c[P],dis[N];
int ans,tl;
struct Edge{ int a,b,v,cost,next; }e[10*N];
void add(int a,int b,int v,int cost) {
e[++cnt].a = a;
e[cnt].b = b;
e[cnt].v = v;
e[cnt].cost = cost;
e[cnt].next = head[a];
head[a] = cnt;
}
inline void add_Node(int a,int b,int vl,int vr,int cost) {
//printf("Node %d %d %d %d\n",a,b,vl,vr);
d[a] -= vl; d[b] += vl;
add(a,b,vr-vl,cost); add(b,a,0,-cost);
}
void paul() {
ss = tot+1; tt = tot+2;
for (int _=1;_<=tot;_++) {
if (d[_] < 0) add(_,tt,-d[_],0) , add(tt,_,0,0);
if (d[_] > 0) add(ss,_, d[_],0) , add(_,ss,0,0);
}
}
#define cp e[i].v
#define B e[i].b
bool SPFA() {
bool flag = false;
memset(p,0,sizeof(p));
memset(dis,127/3,sizeof(dis));
dis[ss] = 0;
queue q; q.push(ss);
while (!q.empty()) {
int u = q.front(); q.pop();
if (u == tt) flag = true;
for (int i=head[u];i;i=e[i].next)
if (cp > 0 && dis[u] + e[i].cost < dis[B]) {
dis[B] = dis[u] + e[i].cost;
p[B] = i;
q.push(B);
}
}
return flag;
}
void mcf() {
int g = p[tt] , flow = INF;
while (g) {
flow = min(flow , e[g].v);
g = p[ e[g].a ];
}
g = p[tt];
while (g) {
e[g ].v -= flow;
e[g^1].v += flow;
ans += e[g].cost * flow;
g = p[ e[g].a ];
}
tl += flow;
}
void init() {
memset(head,0,sizeof(head));
memset(e,0,sizeof(e));
memset(d,0,sizeof(d));
//memset(qlr,0,sizeof(qlr));
//memset(qrr,0,sizeof(qrr));
//memset(qlc,0,sizeof(qlc));
//memset(qrc,0,sizeof(qrc));
memset(sc,0,sizeof(sc));
memset(sr,0,sizeof(sr));
memset(c,0,sizeof(c));
memset(r,0,sizeof(r));
memset(map,0,sizeof(map));
cnt = 1; tot = 0;
S = ++tot; T = ++tot; add_Node(T,S,0,INF,0);
ans = tl = 0;
}
int main() {
#ifndef ONLINE_JUDGE
freopen("5.in","r",stdin);
#endif
while (~scanf("%d",&n)) {
init();
for (int i=1;i<=n;i++) for (int j=1;j<=n;j++) {
scanf("%d",&map[i][j]);
if (map[i][j]) sr[i]++ ,sc[j]++;
}
for (int i=1;i<=n;i++) r[i] = ++tot , c[i] = ++tot;
for (int i=1;i<=n;i++) {
scanf("%d%d",&qlr[i],&qrr[i]);
add_Node(S,r[i],sr[i],sr[i],0); //³¬¼¶Ô´ --> µÚiÐÐ
add_Node(r[i],T,qlr[i],qrr[i],0); //µÚiÐÐ --> ³¬¼¶»ã
}
for (int i=1;i<=n;i++) {
scanf("%d%d",&qlc[i],&qrc[i]);
add_Node(S,c[i],sc[i],sc[i],0); //³¬¼¶Ô´ --> µÚiÁÐ
add_Node(c[i],T,qlc[i],qrc[i],0); //µÚiÁÐ --> ³¬¼¶»ã
}
for (int i=1;i<=n*n/2;i++) {
int x1,y1,x2,y2;
scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
if (map[x1][y1] == map[x2][y2]) continue;
if (!map[x1][y1]) swap(x1,x2) , swap(y1,y2);
if (x1 == x2) add_Node(c[y1],c[y2],0,1,1); //Èç¹ûÔÚͬһÐÐ ¾ÍÔÚÁÐÖ®¼äÁ¬±ß
if (y1 == y2) add_Node(r[x1],r[x2],0,1,1); //Èç¹ûÔÚͬһÁÐ ¾ÍÔÚÐÐÖ®¼äÁ¬±ß
}
paul(); //²¹ÉÏËùÓвðµÄ±ß
//for (int i=2;i<=cnt;i+=2) if (e[i].v) printf("%d %d %d %d\n",e[i].a,e[i].b,e[i].v,e[i].cost);
while (SPFA())
mcf();
//for (int i=3;i<=cnt;i+=2) if (e[i].v) printf("%d %d %d\n",e[i].b,e[i].a,e[i].v);
for (int i=head[ss];i;i=e[i].next) if (e[i].v) ans = -1;//ÅжÏÊÇ·ñÓнâ
if (ans == -1) puts("-1"); else printf("%d\n",ans);
}
return 0;
}