C++ program to calculate how many years needed to get X rupees with 1% interest

Suppose we have a number X. We have 100 rupees in a bank. The bank returns annual interest rate of 1 % compounded annually. (Integers only). We have to check how many years we need to get X rupees?

So, if the input is like X = 520, then the output will be 213.

Steps

To solve this, we will follow these steps −

sum := 0 balance := 100 while balance < n, do:    interest := balance / 100    sum := sum + 1    balance := balance + interest return sum

Example

Let us see the following implementation to get better understanding −

#include <bits/stdc++.h> using namespace std; int solve(int n){    int sum = 0;    int balance = 100;    while (balance < n){       int interest = balance / 100;       sum = sum + 1;       balance = balance + interest;    }    return sum; } int main(){    int X = 520;    cout << solve(X) << endl; }

Input

520

Output

213