convert int to decimal program code example

Example 1: built in function in c++ for binary to decimal

#include <bits/stdc++.h>

using namespace std;

int main(void){
    bitset<8> bits("1000");
    int ab = bits.to_ulong();
    cout << ab << "\n";
    
    return 0;
}

Example 2: how to convert a binary number to decimal in C

#include <math.h>
#include <stdio.h>
int convert(long long n);
int main() {
    long long n;
    printf("Enter a binary number: ");
    scanf("%lld", &n);
    printf("%lld in binary = %d in decimal", n, convert(n));
    return 0;
}

int convert(long long n) {
    int dec = 0, i = 0, rem;
    while (n != 0) {
        rem = n % 10;
        n /= 10;
        dec += rem * pow(2, i);
        ++i;
    }
    return dec;
}