Problem:
Score : 100 points

Problem Statement

In AtCoder City, there are three stations numbered 1, 2, and 3.

Each of these stations is operated by one of the two railway companies, A and B. A string S of length 3 represents which company operates each station. If S_i is A, Company A operates Station i; if S_i is B, Company B operates Station i.

To improve the transportation condition, for each pair of a station operated by Company A and one operated by Company B, there will be a bus service connecting them.

Determine if there is a pair of stations that will be connected by a bus service.

Constraints

Each character of S is A or B.

|S| = 3

Input

Input is given from Standard Input in the following format:

S

Output

If there is a pair of stations that will be connected by a bus service, print Yes; otherwise, print No.

Sample Input 1

ABA

Sample Output 1

Yes

Company A operates Station 1 and 3, while Company B operates Station 2.

There will be a bus service between Station 1 and 2, and between Station 2 and 3, so print Yes.

Sample Input 2

BBA

Sample Output 2

Yes

Company B operates Station 1 and 2, while Company A operates Station 3.

There will be a bus service between Station 1 and 3, and between Station 2 and 3, so print Yes.

Sample Input 3

BBB

Sample Output 3

No

Company B operates all the stations. Thus, there will be no bus service, so print No.

Solution in JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

'use strict';
function Main(input) {
  let stations = input.split("");
  stations = stations.map(v => v.toUpperCase());
  
  const stationsLen = stations.length;
  const arr = [];
  for (let i = 0; i < stationsLen; ++i){
    arr.push(new Array(stationsLen).fill(false));
  }
  
  for (let i = 0; i < stationsLen; ++i) {
    for (let j = 0; j < stationsLen; ++j) {
      arr[i][j] = stations[i] !== stations[j];
    }
  }
  
  let hasBus = false;
  let len = arr.length;
  main: for (let i = 0; i < len; ++i) {
    for (let j = 0; j < len; ++j) {
      if ( arr[i][j] ) { 
        hasBus = true; 
        break main; 
      }
    }
  }
  console.log(hasBus ? 'Yes' : 'No');
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));