找出最大矩阵，并返回其面积

#include <stdio.h>
#include <stdint.h>

int main( void )
{
    size_t map[][5] = { {1, 0, 1, 0, 0}
                      , {1, 0, 1, 1, 1}
                      , {1, 1, 1, 1, 1}
                      , {1, 0, 0, 1, 0} };

    ///////////////////////////////////////////////

    const size_t row = sizeof(map)/sizeof(*map);
    const size_t col = sizeof(*map)/sizeof(**map);
    for( size_t c=0; c!=col; ++c )
    {
        size_t deepth = 0;
        for( size_t r=0; r!=row; ++r )
        {
            if( map[r][c] != 0 )
                map[r][c] = ++deepth;
            else
                deepth = 0;
        }
    }

    size_t s_max = 0;
    for( size_t r=0; r!=row; ++r )
    {
        for( size_t c=0; c!=col; ++c )
        {
            size_t deepth = SIZE_MAX;
            for( size_t width=0; c+width!=col && map[r][c+width]!=0; ++width )
            {
                deepth = deepth<map[r][c+width] ? deepth : map[r][c+width];
                s_max = s_max>(width+1)*deepth ? s_max : (width+1)*deepth;
            }
        }
    }
   printf( "%zu\n", s_max );
}