Money with Baba

Calculate the initial amount of money Baba had before donating to beggars

Understand the Problem

Problem Statement

Baba is very kind to beggars and every day Baba donates half of the amount he has when ever a beggar requests him. The money M left in Baba's hand is passed as the input and the number of beggars B who received the alms are passed as the input. The program must print the money Baba had in the beginning of the day.

Constraints

Money left (M) must be a non-negative integer
Number of beggars (B) must be a non-negative integer
Initial money will not exceed standard integer limits
If M or B is 0, Baba had 0 money initially

Examples

Example 1

Input

100
2

Output

Explanation

Baba donated to two beggars. After giving to the second beggar, he had Rs.100. Before that donation, he had 100×2 = Rs.200. Before the first donation, he had 200×2 = Rs.400. So Baba started with Rs.400.

Solution

#include <stdio.h>
#include <math.h>

int main() {
    int M, B;
    scanf("%d", &M);
    scanf("%d", &B);
    
    if (M == 0 || B == 0) {
        printf("0\n");
    } else {
        int initial = M * (int)pow(2, B);
        printf("%d\n", initial);
    }
    
    return 0;
}

Time:O(1) - Constant time using mathematical power function

Space:O(1) - Constant space, only using a few variables

Approach:

Step-by-step explanation:

Include necessary headers: stdio.h for input/output and math.h for the pow() function
Declare variables M (money left) and B (number of beggars)
Read input values using scanf()
Check edge case: if either M or B is 0, Baba had 0 money initially
Otherwise, calculate initial money as M × 2^B using pow() function
Print the result using printf()

Visual Explanation

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