TOJ 3009.Monkey Vines

题目链接 : http://acm.tju.edu.cn/toj/showp3009.html

Deep in the Amazon jungle, exceptionally tall trees grow that support a rich biosphere of figs and juniper bugs, which happen to be the culinary delight of brown monkeys.
Reaching the canopy of these trees requires the monkeys to perform careful navigation through the tall tree’s fragile vine system. These vines operate like a see-saw: an unbalancing of weight at any vine junction would snap the vine from the tree, and the monkeys would plummet to the ground below. The monkeys have figured out that if they work together to keep the vines properly balanced, they can all feast on the figs and juniper bugs in the canopy of the trees.

A vine junction supports exactly two sub-vines, each of which must contain the same number of monkeys, or else the vine will break, leaving a pile of dead monkeys on the jungle ground. For purposes of this problem, a vine junction is denoted by a pair of matching square brackets [ ], which may contain nested information about junctions further down its sub-vines. The nesting of vines will go no further than 25 levels deep.
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这道题最大的难点在于要读懂题目：要让树保持平衡，需要多大。分析一下就知道关键是找到树的深度，题目不难。需要注意的是如果要读一行字符串用gets()函数，scanf()不能读空格、换行。

#include <stdio.h>
#include <iostream>
#include <math.h>
#include <cstring>
using namespace std;
int main(){
    int n,max,tmp;
    char vine[152];
    scanf("%d",&n);
    getchar();
    for(int cast=1;cast<=n;cast++){
        gets(vine);
        tmp=max=0;
        for(int i=0;i<strlen(vine);i++){
            if(vine[i]=='[') tmp++;
            else if(vine[i]==']') tmp--;
            if(tmp>max)
                max=tmp;
        }
        printf("%d %d\n",cast,int(pow(2.0,max)));
    }
}