4443: [Scoi2015] small convex play matrix

4443: [Scoi2015] small convex play matrixDescriptionsmall Convex and Xiao Fang is a good friend, small square to small convex a n*m (n<=m) matrix A, ask for a small bald from which n number, where any two numbers can not be in the same row or the same column, now the small convex want to know the number of the selected n number of K the minimum value is how much. Inputthe first line gives three integers n,m,knext n rows, m numbers per line, to describe this matrixOutputtitleSample Input3 4 2
1 5 6 6
8 3 4 3
6 8 6 3Sample Output3HINT

1<=k<=n<=m<=250,1<= Matrix Element <=10^9

acty really big God!!! (Everyone is free to go to the Bzoj to search)————— the following ——————It is easy to see that the answer is two-point. The title said is the first k big, actually is the first n-k+1 small (always see wrong) ... every time we verify the mid, we put the number of <=mid in the matrix about coordinates, run the maximum match of the binary graph, and judge whether the maximum match number is greater than n-k+1.

#include <stdio.h>#include<iostream>#include<algorithm>using namespacestd;Const intn=255;intN,m,k,i,j,ans,a[n][n],f[n],p[n];inttot,head[n],next[n*n],to[n*N];voidAddintXinty) {Tot++; To[tot]=y; Next[tot]=Head[x]; HEAD[X]=tot;}intDfsintXintT) {    inti;  for(i=head[x];i!=-1; i=Next[i])if(p[to[i]]!=T) {inty=To[i]; P[y]=T; if(f[y]==0||DFS (F[Y],T)) {F[y]=x; return 1; }    }    return 0;}intErfen (intLintR) {    if(L>r)returnl; intMid= (l+r) >>1, i,j,ans=0; Tot=0;  for(i=1; i<=n;i++) Head[i]=-1;  for(i=1; i<=m;i++) P[i]=f[i]=0;  for(i=1; i<=n;i++)      for(j=1; j<=m;j++)     if(a[i][j]<=mid) Add (I,J);  for(i=1; i<=n;i++) ans+=DFS (i,i); if(ans>=n-k+1)returnErfen (l,mid-1);Else    returnErfen (mid+1, R);}intMain () {scanf ("%d%d%d",&n,&m,&k);  for(i=1; i<=n;i++)      for(j=1; j<=m;j++) {scanf ("%d",&A[i][j]); Ans=Max (ans,a[i][j]); } cout<<erfen (1, ans); return 0;}

4443: [Scoi2015] small convex play matrix