0_0_34981112_24378.cpp:21:11: error: '::main' must return 'int' void main(){ ^ 0_0_34981112_24378.cpp: In function 'int main()': 0_0_34981112_24378.cpp:28:34: error: 'memset' was not declared in this scope memset(d,-1,sizeof(d)); ^