C :

#include<stdio.h>
#include<stdlib.h>

int main()
{ 
  int ans[128];
  int i,n,flag;
  char str[10];
  while(gets(str)){
    n=strlen(str);
    for(i=0;i<128;i++)
      ans[i]=0;
    for(i=0;i<n;i++)
      ans[str[i]]++;
    for(flag=i=0;i<128;i++)
      if(ans[i]%2)flag++;
    if(flag<2)printf("Yes\n");
      else printf("No\n");
  }
  return 0;
}

C++ :

#include<iostream>
#include<cmath>  
#include<queue>
#include<stack>
#include<vector>  
#include<algorithm>  
#include<cstdio>  
#include<cstring>  
using namespace std;  
#define N 10010


int main()
{
	int i, j;
	char s[100];
	while(cin >> s){
		int cnt[300] = {0};
		for(i=0; s[i] != 0; i++){
			cnt[s[i]]++;
		}
		int len = strlen(s);
		int jishu = 0;
		for(i=0; i<300; i++){
			if(cnt[i] % 2) jishu++;
		}
		if(len % 2 == 0 && jishu == 0){
			cout << "Yes\n";
		}
		else if(len % 2 == 1 && jishu == 1){
			cout << "Yes\n";
		}
		else{
			cout << "No\n";
		}
	}
	return 0;
}

Pascal :

var s:string;
procedure pd;
var i,k,n:longint;
    a,b:array[0..1000] of longint;
begin
  fillchar(a,sizeof(a),0);
  fillchar(b,sizeof(b),0);
  k:=0;
  for i:=1 to length(s) do
   begin
    if b[ord(s[i])]=0 then
     begin
      inc(k);
      a[k]:=ord(s[i]);
     end;
     inc(b[ord(s[i])]);
   end;
  n:=0;
  for i:=1 to k do if b[a[i]] mod 2=1 then inc(n);
  if n<=1 then writeln('Yes') else writeln('No');
end;
begin
  while not eof do
   begin
     readln(s);
     if length(s)=0 then exit;
     if length(s)=1 then writeln('Yes') else pd;
   end;
end.

Java :

import java.util.Scanner;


public class Main {
		public	static void main (String[] args ) {
			Scanner in=new Scanner(System.in);
			while (in.hasNext()) {
				String s=in.next();char [] a=new char[s.length()];int []b=new int[s.length()];
				for(int i=0;i<s.length();i++) {
					a[i]=s.charAt(i);
				}
				for(int j=0;j<s.length();j++) {int con=0;
					for(int x=0;x<s.length();x++) {
						if(s.charAt(j)==a[x]) {
							con++;
						}
					}
					b[j]=con;
				}int sum=0;
				for(int y=0;y<s.length();y++) {
					if(b[y]==1) {
						sum++;
					}
				}
				if(sum>=2) {
					System.out.println("No");
				}
				else
					System.out.println("Yes");
				
			}
		}
}