AtCoder Beginner Contest 044 B - 美しい文字列 / Beautiful Strings

Time limit : 2sec / Memory limit : 256MB

Score : 200 points

Problem Statement

Let w be a string consisting of lowercase letters. We will call w beautiful if the following condition is satisfied:

• Each lowercase letter of the English alphabet occurs even number of times in w.

You are given the string w. Determine if w is beautiful.

Constraints

• 1≤|w|≤100
• w consists of lowercase letters (a-z).

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Input

The input is given from Standard Input in the following format:

w

Output

Print Yes if w is beautiful. Print No otherwise.

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Sample Input 1

Copy

abaccaba

Sample Output 1

Copy

Yes

a occurs four times, b occurs twice, c occurs twice and the other letters occur zero times.

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Sample Input 2

Copy

hthth

Sample Output 2

Copy

No

题解：很简单 但是没有考虑长度为一的时候哇了两发

#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cstdlib>
#include <iomanip>
#include <cmath>
#include <ctime>
#include <map>
#include <set>
#include <queue>
#include <stack>
using namespace std;
#define lowbit(x) (x&(-x))
#define max(x,y) (x>y?x:y)
#define min(x,y) (x<y?x:y)
#define MAX 100000000000000000
#define MOD 1000000007
#define pi acos(-1.0)
#define ei exp(1)
#define PI 3.141592653589793238462
#define INF 0x3f3f3f3f3f
#define mem(a) (memset(a,0,sizeof(a)))
typedef long long ll;
ll gcd(ll a,ll b){
    return b?gcd(b,a%b):a;
}
bool cmp(int x,int y)
{
    return x>y;
}
const int N=10005;
const int mod=1e9+7;
int main()
{
    std::ios::sync_with_stdio(false);
    char a[101];
    scanf("%s",a);
    int len=strlen(a);
    if(len==1) {
        cout<<"No"<<endl;
        return 0;
    }
    sort(a,a+len);
    int t=1,flag=1;
    for(int i=1;i<len;i++){
        if(a[i]==a[i-1]) t++;
        else{
            if(t%2==1) {
                flag=0;
                break;
            }
            else t=1;
        }
    }
    if(flag) cout<<"Yes"<<endl;
    else cout<<"No"<<endl;
    return 0;
}