NOIP 考前 队列复习

BZOJ 1127

 #include <cstdio>
 #include <cstring>
 #include <iostream>
 #include <algorithm>
 #define M 2020
 using namespace std;
 int n,k,a[M][M];
 long long sum[M][M];
 long long Get_Sum(int x1,int y1,int x2,int y2)
 {
     return sum[x2][y2]-sum[x1-][y2]-sum[x2][y1-]+sum[x1-][y1-];
 }
 void Output(int x1,int y1,int x2,int y2)
 {
     while( Get_Sum(x1,y1,x2,y2)>k* )
     {
         if(x1==x2)
             y2--;
         else
         {
             if( Get_Sum(x1+,y1,x2,y2)>=k )
                 x1++;
             else
                 x2--;
         }
     }
     printf("%d %d %d %d\n",y1,x1,y2,x2);
     exit();
 }
 void Monotonous_Stack(int base,int h[])
 {
     static int stack[M],top;
     static int l[M],r[M];
     int i;

     for(top=,i=;i<=n+;i++)
     {
         while( top && h[stack[top]]>h[i] )
             r[stack[top--]]=i-;
         stack[++top]=i;
     }
     for(top=,i=n;i>=;i--)
     {
         while( top && h[stack[top]]>h[i] )
             l[stack[top--]]=i+;
         stack[++top]=i;
     }
     for(i=;i<=n;i++)
         if(h[i])
         {
             long long temp=Get_Sum(base-h[i]+,l[i],base,r[i]);
             if( temp>=k )
                 Output(base-h[i]+,l[i],base,r[i]);
         }
 }
 int main()
 {
     int i,j;
     cin>>k>>n;
     for(i=;i<=n;i++)
         for(j=;j<=n;j++)
         {
             scanf("%d",&a[i][j]);
             if( a[i][j]>=k && a[i][j]<=k* )
             {
                 printf("%d %d %d %d\n",j,i,j,i);
                 return ;
             }
             sum[i][j]=sum[i-][j]+sum[i][j-]-sum[i-][j-]+a[i][j];
         }
     static int h[M];
     for(i=;i<=n;i++)
     {
         for(j=;j<=n;j++)
             h[j]=a[i][j]>k*?:h[j]+;
         Monotonous_Stack(i,h);
     }
     puts("NIE");
     return ;
 }

BZOJ 1127