10176 - Ocean Deep! - Make it shallow!!

Problem Link : https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1117

Solution idea : take every digit and represent it in decimal and mod it.. update the result every time...if the final result is divisible by m than ans is YES.

Solution : 

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

ll int bigmod(ll int b,ll int p,ll int m)
{
    if(p==0) return 1%m;

    else if(p%2==0)
    {
        ll int y= bigmod(b,p/2,m);

        return (y*y)%m;
    }
    else return (b*(bigmod(b,p-1,m)))%m;
}

ll int s[10002];

int main()
{
    char ch;
    ll int index,m=131071,res,val;

    while(scanf("%ch",&ch)==1)
    {
        index=0;
        s[index]=ch-48;
        index++;
        res=0;
        val=0;
        while(scanf("%ch",&ch)==1)
        {
            if(ch=='#') break;
            if(ch=='1'||ch=='0')
            {
                s[index]=ch-48;
                index++;
            }

        }
        getchar();
        for(ll int i=0; i<index; i++)
        {
            val=(s[i]*bigmod(2,index-1-i,m))%m;
            res=res+val;
        }
        if(res%m==0) printf("YES\n");
        else printf("NO\n");
    }

}