loading...

Daily Coding Challenge #48

wingkwong profile image Wing-Kam ・2 min read

About

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.


/*
AtCoder Beginner Contest 172 - A - Calc
https://atcoder.jp/contests/abc172/tasks/abc172_a
*/

#include <bits/stdc++.h>
using namespace std; 

#define FAST_INP  ios_base::sync_with_stdio(false);cin.tie(NULL)
int main()  
{ 
    FAST_INP;
    int a;
    // read the input
    cin >> a;
    // print the value a+a^2+a^3
    cout << ((a) + (a*a) + (a*a*a)) << "\n";
    return 0;
} 


/*
AtCoder Beginner Contest 172 - B - Minor Change
https://atcoder.jp/contests/abc172/tasks/abc172_b
*/

#include <bits/stdc++.h>
using namespace std; 

#define FAST_INP  ios_base::sync_with_stdio(false);cin.tie(NULL)
int main()  
{ 
    FAST_INP;
    string s,t;
    cin >> s >> t;
    int n = (int)s.size();
    int ans=0;
    // choose one character of S and replace it with a different character
    for(int i=0;i<n;i++){
        if(s[i]!=t[i]) ans++;
    }
    cout << ans << "\n";
    return 0;
} 


/*
AtCoder Beginner Contest 172 - D - Sum of Divisors
https://atcoder.jp/contests/abc172/tasks/abc172_d
*/

#include <bits/stdc++.h>
using namespace std; 

#define FAST_INP  ios_base::sync_with_stdio(false);cin.tie(NULL)

int main()  
{ 
    FAST_INP;
    int n;
    cin >> n;
    vector<long long> d(n+1,0);
    long long ans=0;
    for(int i=1;i<=n;i++){
        for (int j=1;j*i<=n;j++) {
            // d(X) be the number of positive divisors of X .
            d[i*j]++; 
        }
    }

    for(int i=1;i<=n;i++){
        // find ∑N K=1 K*d(K)
        ans+=i*d[i];
    } 

    cout << ans;
    return 0;
} 


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

GitHub logo wingkwong / leetcode

🏆 A Collection of my LeetCode Solutions with Explanations 🏆

GitHub logo wingkwong / hackerrank

🏆 A Collection of my HackerRank Solutions with Explanations 🏆

GitHub logo wingkwong / codeforces

🏆 A Collection of my Codeforces Solutions with Explanations 🏆

GitHub logo wingkwong / atcoder

🏆 A Collection of my AtCoder Solutions with Explanations 🏆

Posted on by:

wingkwong profile

Wing-Kam

@wingkwong

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

Discussion

pic
Editor guide