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=;
 const int mod=1e9+;
 int main()
 {
     std::ios::sync_with_stdio(false);
     char a[];
     scanf("%s",a);
     int len=strlen(a);
     if(len==) {
         cout<<"No"<<endl;
         return ;
     }
     sort(a,a+len);
     int t=,flag=;
     for(int i=;i<len;i++){
         if(a[i]==a[i-]) t++;
         else{
             if(t%==) {
                 flag=;
                 break;
             }
             else t=;
         }
     }
     if(flag) cout<<"Yes"<<endl;
     else cout<<"No"<<endl;
     return ;
 }