bzoj1047: [HAOI2007] Ideal Square

Good God's monotonous stack ah ...

#include <cstdio> #include <cstring> #include <iostream> #include <algorithm>using namespace STD, #define REP (i,s,t) for (Register int. i=s;i<=t;i++) #define DWN (i,s,t) for (register int i=s;i>=t;i--) #define CLR    (x,c) memset (x,c,sizeof (x)) int read () {int X=0;char c=getchar ();    while (!isdigit (c)) C=getchar ();    while (IsDigit (c)) x=x*10+c-' 0 ', C=getchar (); return x;} const int Nmax=1005;const int Inf=0x7f7f7f7f;int a[nmax][nmax],n,m,b;int q[nmax],mx[nmax][nmax],mn[nmax][nmax],ans[        Nmax],res[nmax];void Solve () {rep (i,1,n) {int l=1,r=0;            Rep (j,1,m) {if (q[l]<=j-b) l++;            while (L<=r&&a[i][q[r]]<=a[i][j]) r--;            Q[++r]=j;        if (j>=b) mx[i][j]=a[i][q[l]];        } l=1,r=0;            Rep (j,1,m) {if (q[l]<=j-b) l++;            while (L<=r&&a[i][q[r]]>=a[i][j]) r--;            Q[++r]=j;        if (j>=b) mn[i][j]=a[i][q[l]]; }}/*rep (I,1,n) {REP (j,b,m) printf ("%d", Mx[i][j]);p rintf ("\ n");    } printf ("\ n");    Rep (I,1,n) {rep (j,b,m) printf ("%d", Mn[i][j]);p rintf ("\ n"); } printf ("\ n"); */}void mins (int &a,int b) {if (a>b) a=b;}    void work () {int ret=inf;        Rep (j,b,m) {int l=1,r=0;            Rep (i,1,n) {if (q[l]<=i-b) l++;            while (L<=r&&mx[q[r]][j]<=mx[i][j]) r--;            Q[++r]=i;        if (i>=b) ans[i]=mx[q[l]][j];        } l=1,r=0;            Rep (i,1,n) {if (q[l]<=i-b) l++;            while (L<=r&&mn[q[r]][j]>=mn[i][j]) r--;            Q[++r]=i;        if (i>=b) res[i]=mn[q[l]][j];    } Rep (i,b,n) mins (ret,ans[i]-res[i]); } printf ("%d\n", ret);}    int main () {N=read (), M=read (), B=read ();    Rep (I,1,n) Rep (j,1,m) A[i][j]=read ();    Solve (); work (); return 0;}

　　

1047: [HAOI2007] Ideal square time limit:10 Sec Memory limit:162 MB
submit:2702 solved:1465
[Submit] [Status] [Discuss] Description

There is a matrix of a*b integers, now ask you to find a n*n square area, so that the maximum and minimum values of all the numbers in the region
The difference is minimal.

Input

The first behavior is 3 integers, which represent the value of A,b,n the second row to the a+1 line each behavior b nonnegative integer, representing the number in the corresponding position in the matrix. Every
Rows are separated by a space between two adjacent numbers.
100% of Data 2<=a,b<=1000,n<=a,n<=b,n<=100

Output

Only one integer, which is the minimum value of the difference between the maximum and minimum integers in all the n*n square areas in the a*b matrix.

Sample Input5 4 2
1 2 5 6
0 17 16 0
16 17 2 1
2 10 2 1
1 2 2 2Sample Output1HINT Source [Submit] [Status] [Discuss]

bzoj1047: [HAOI2007] Ideal square