"NOIP Simulation" Assassination of Ambassadors (two-point answer + and check set)

" Solution" "Two-point answer "

"See the maximum value of the smallest, that must be two points, ah, the exam did not know what the brain did go ..." "

"First find the largest value in the entire matrix, as the right boundary of the two points, and then, the two-point answer, the matching conditions of the adjacent lattice and check set and to a set, when using less than equal to the current value of the lattice can be 1 and n*m Unicom, the current value is valid"

#include <cstdio> #include <cstring> #include <algorithm> using namespace std;
int N,M,A[1010][1010],ANS,MAXN;
int f[1000010];
	int find (int x) {if (f[x]==x) return f[x];
	F[x]=find (F[x]);
 return f[x];
	} inline void link (int x,int y) {int f1=find (x), F2=find (y);
F[F1]=F2;
	} inline bool Check (int t) {for (int i=1;i<=n*m;++i) f[i]=i;
	   	for (int i=1;i<=n;++i) for (int j=1;j<=m;++j) if (a[i][j]<=t) {int now= (i-1) *m+j;
	   	if (i+1<=n&&a[i+1][j]<=t) link (now,i*m+j);
	   if (j+1<=m&&a[i][j+1]<=t) link (now,now+1);
	} if (find (1) ==find (n*m)) return 1;
return 0;
	} inline void qsort (int l,int r) {int mid;
	 	while (l<=r) {mid= (l+r) >>1;
	 	 if (check (mid)) R=mid-1,ans=mid;
	 else l=mid+1;
	}} int main () {freopen ("murder.in", "R", stdin);
	Freopen ("Murder.out", "w", stdout);
	int i,j;
	scanf ("%d%d", &n,&m); for (I=1;i<=n;++i) for (j=1;j<=m;++j) scanf ("%d", &a[i][j]), Maxn=max (A[I][J],MAXN);
	Qsort (0,MAXN);
	printf ("%d\n", ans);
 return 0;  }