帮我看一下
#include <stdio.h> float cost; extern float money(float s) { if(s <= 3) { return cost = 13; } else { return cost = money(s-1) + 2.3; } } int main() { float rmb = money(12);//这里要放在main函数里面 float R= rmb * 1.2; printf("每天打车费用%f",R); return 0; }