Main.cc: In function ‘void init()’: Main.cc:15:10: error: ‘sy’ was not declared in this scope swap(sy[i],dy[j-1]); ^~ Main.cc:15:10: note: suggested alternative: ‘dy’ swap(sy[i],dy[j-1]); ^~ dy Main.cc: In function ‘int main()’: Main.cc:25:9: error: ‘j’ was not declared in this scope if(dx[j]>dx[i]&&dy[j]