实例18

// Created by www.runoob.com on 15/11/9.
// Copyright @ 2015年 菜鸟教程. All rights reserved.
//

#include<stdio.h>
#include<stdio.h>
int main(){
int day, x1 = 0, x2;
day=9;
x2=1;
while(day>0) {
x1=(x2+1)*2; // day第一天的桃子数是第二天桃子数的2倍
x2=x1;
day–;
}
printf(“总数为 %d\n”,x1);

return 0;

}