View Compilation Error

0_0_17990647_14474.cpp: In function 'int main()':
0_0_17990647_14474.cpp:182:18: error: incompatible types in assignment of 'int' to 'int [1010][1010]'
                 a=sum(x_top,y_top);
                  ^
0_0_17990647_14474.cpp:183:17: error: 'b' was not declared in this scope
                 b=sum(x_bot-1,y_bot-1);
                 ^
0_0_17990647_14474.cpp:184:17: error: 'c' was not declared in this scope
                 c=sum(x_bot-1,y_top);
                 ^
0_0_17990647_14474.cpp:185:17: error: 'd' was not declared in this scope
                 d=sum(x_top,y_bot-1);
                 ^