ZOJ 3810 - A Volcanic Island （ 构造 ）

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
#define MAXN 111
#define CLR( a,b ) memset( a, b, sizeof(a) )

int g[MAXN][MAXN];
char color[] = "RGB";
int T, n;

void solve()
{
    CLR( g, -1 );
    int col = 1 ,i, j, k, ct;
    for( i = 0; i < n; ++i )
        g[i][n-1] = 0;

    k = n >> 1;
    //printf( "k = %d\n", k );

    for( i = 0; i < k; ++i )
    {
        if( i & 1 )
        {
            for( j = 0; j < n-1-i; ++j )
                g[i][j] = col;
            int ct = 0;
            for( j = 0; ct <= i; j++, ct++ )
                g[i+1][j] = col;
        }
        else
        {
            for( j = 0; j < n-1-i; ++j )
                g[i][j+i] = col;
            int ct = 0;
            for( j = n-2; ct <= i; j--, ct++ )
                g[i+1][j] = col;
        }
        col++;
    }

    if( (k & 1) == 0 )
    {
        for( i = k; i < n; ++i )
        {
            ct = n, j = 0;
            while( true )
            {
                if( g[i][j] == -1 )
                    g[i][j] = col, ct--;
                j++;
                if( j >= n-1 )
                    break;
            }
            for( j = 0; ct > 0; ++j, ct-- )
                g[i+1][j] = col;
            col++;
        }
        swap( g[n-1][0], g[n-3][n-2] );
    }
    else
    {
        for( i = k; i < n-1; ++i )
        {
            for( j = 0; j < n-i-1; ++j )
                g[i][j] = col;
            for( --j; j < n-1; ++j )
                g[i+1][j] = col;
            col++;
        }
        swap( g[n-1][n-2], g[n-3][0] );
    }


    for( i = 0; i < n; ++i )
    {
        if( i != 0 )    putchar( ‘\n‘ );
        for( j = 0; j < n; ++j )
        {
            if( g[i][j] == 0 ) putchar(‘Y‘);
            else printf( "%c", color[g[i][j] % 3] );
            //printf( "%d", g[i][j] );
        }

    }
    putchar( ‘\n‘ );
}

void Orz()
{
    scanf( "%d", &T );
    while( T-- )
    {
        scanf( "%d", &n );
        if( n == 1 )        puts( "Y");
        else if( n <= 4 )   puts( "No solution!" );
        else if( n == 5 )
        {
            printf( "RRRRY\n" );
            printf( "BGRGY\n" );
            printf( "BGGGY\n" );
            printf( "BRRRY\n" );
            printf( "BBRRY\n" );
        }
        else if( n == 6 )
        {
            printf( "RRRRRY\n" );
            printf( "BBBBRY\n" );
            printf( "GGGBBY\n" );
            printf( "RRGGYY\n" );
            printf( "RRGBBY\n" );
            printf( "RRBBBB\n" );
        }
        else
        {
            solve();
        }
    }
}

int main()
{
    Orz();
    return 0;
}