# Daily Coding Challenge #82

This is a series of Daily Coding Challenge. Each day I show a few solutions written in C++. The questions are from coding practice/contest sites such as HackerRank, LeetCode, Codeforces, Atcoder and etc.

/*
Educational Codeforces Round 92 (Rated for Div. 2) - A. LCM Problem
https://codeforces.com/contest/1389/problem/A
*/

#include <bits/stdc++.h>
using namespace std;
#define FAST_INP  ios_base::sync_with_stdio(false);cin.tie(NULL)

int main()
{
FAST_INP;
long long l, r, t;
cin>>t;
while(t--){
cin>>l>>r;
// if the upper number is multiple of the lower number
// and the upper number is within [l,r]
// e.g. LCM(a,b) where b is a*2 = b
if(2*l<=r) cout<<l<<" "<<2*l<<endl;
else cout<<-1<<" "<<-1<<endl;
}
return 0;
}


/*
Educational Codeforces Round 92 (Rated for Div. 2) - C. Good String
https://codeforces.com/contest/1389/problem/C
*/

#include <bits/stdc++.h>
using namespace std;
#define FAST_INP  ios_base::sync_with_stdio(false);cin.tie(NULL)

void solve() {
// tkt1t2...tk-1 and t2t3...tkt1
// so tk=t2, t1=t3, t2=t4 ...
// even length: ABABABAB
// odd length: AAAAA
// brute force all possible combinations
string s;
cin >> s;
int ans = 0;
for (char i = '0'; i <= '9'; i++) {
for (char j = '0'; j <= '9'; j++) {
char x=i, y=j;
int cnt = 0;
for(char c:s){
if(c==x){
cnt++;
swap(x,y);
}
}
if(i==j) ans=max(ans,cnt);
// if the cnt is odd and i!=j, cnt=cnt--;
else ans=max(ans,cnt&~1);
}
}
cout << (s.size() - ans) << endl;
}

int main() {
FAST_INP;
int t;
string s;
cin >> t;
while (t--) {
solve();
}
return 0;
}


The source code is available in corresponding repo below. Star and watch for timely updates!

## wingkwong / atcoder

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### Wing-Kam

Consultant by day. Developer by night. AWS certified. Exploring #CloudNative currently.