0_0_38359793_28875.cpp: In function 'int main()': 0_0_38359793_28875.cpp:74:121: error: 'cal_pos' was not declared in this scope int s = rec[calPos(x2, y2)] - rec[calPos(x2, y1 - 1)] - rec[calPos(x1 - 1, y2)] + rec[cal_pos(x1 - 1, y1 - 1)]; ^