Contest3147 - game 38 of 2021 Freshmen's personal training match_ G: Flower bed

 

 

//
#include<bits/stdc++.h>
using namespace std;

// 1 ≤ n ≤ 1000
const int MAXN=2222;
char str[MAXN],ans[MAXN][MAXN];     //  An array type 

void init()
{
    memset( str,0,sizeof( str ) );
    memset( ans,0,sizeof( ans ) );
}

int main()
{
    int n,i,j,p1,p2,cnt; init();    

    while( ~scanf("%d%s",&n,str) )
    {
        p1=1; p2=2*n-1; cnt=0;
        while( p1<=p2 )
        {
            for( i=p1;i<=p2;i++ ) ans[i][p1]=ans[i][p2]=str[cnt];
            for( j=p1;j<=p2;j++ ) ans[p1][j]=ans[p2][j]=str[cnt];

            p1++; p2--; cnt++;      //  One step is enough for both sides 
        }
        for( i=1;i<=2*n-1;i++ )     // ans[0][j]  No data   Out-of-service  %s
        {
            for( j=1;j<=2*n-1;j++ )
            {
                printf("%c",ans[i][j]); 
            }
            printf("\n");
        }
        init(); 
    }
    return 0;
}

//
find:
01  It's complicated at first   Make good use of  while for  Two cycles  

    p1=1        ++
    p2=2*n-1    --

    [p1][p1]~[p1][p2]
    [p1][p1]~[p2][p1]
    ...     ...

02 ans[0][j]  No data   Out-of-service  %s
03  Be careful  init();  The impact of location on data 
04  data type  char  Check  (  With a few   Unskilled  )
05 n<=1000 2*n-1  Be careful of spillage