( A [ i , 0 ] , A [ i , 1 ] ) denotes the coordinate of the bottom left of the rectangle ( A [ i , 2 ] , A [ i , 3 ] ) denotes the coordinate of upper right of the rectangle
int [ , ] A = { { 1 , 3 , 4 , 5 } , { 3 , 1 , 7 , 4 } , { 5 , 3 , 8 , 6 } } ;