Zhejiang version of "C Programming Language (3rd Edition)" title set Exercises 4-10 monkey eating peaches problem (15 points)

Solution: analog, with examples to deduce recursion relations: 10--4--1, relationship oldDay = 2 * (newDay + 1).

#include <stdio.h>
int main()
{
    int N, newDay, oldDay;
    scanf("%d", &N);
    newDay = 1; // 第N天剩1个。
    while (N != 1)
    {                              //推导到第1天时，退出循环。
        oldDay = (newDay + 1) * 2; //前一天的个数。
        newDay = oldDay;
        N--;
    }
    printf("%d\n", oldDay);
    return 0;
}