11029-Leading_and_Trailing.cpp

/*
    written by Pankaj Kumar.
    country:-INDIA
*/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll ;
typedef vector<ll> vl;
typedef vector<bool> vb;
typedef vector<char> vc;
typedef map<ll,ll> ml;
typedef set<char>sc;
typedef set<ll> sl;
#define pan cin.tie(0);cout.tie(0);ios_base::sync_with_stdio(0);
// define values.
// #define mod 1000000007
#define phi 1.618
/* Bit-Stuff */
#define get_set_bits(a) (__builtin_popcount(a))
#define get_set_bitsll(a) ( __builtin_popcountll(a))
#define get_trail_zero(a) (__builtin_ctz(a))
#define get_lead_zero(a) (__builtin_clz(a))
#define get_parity(a) (__builtin_parity(a))
/*  Abbrevations  */
#define ff first
#define ss second
#define mp make_pair
#define line cout<<endl;
#define pb push_back
#define Endl "\n"
// loops
#define forin(arr,n) for(ll i=0;i<n;i++) cin>>arr[i];
// Some print
#define no cout<<"NO"<<endl;
#define yes cout<<"YES"<<endl;
#define cc ll test;cin>>test;while(test--)
// sort
#define all(V) (V).begin(),(V).end()
#define srt(V) sort(all(V))
#define srtGreat(V) sort(all(V),greater<ll>())
// function

ll binpow(ll a, ll b, ll m = 1000)
{
    a %= m;
    ll res = 1;
    while(b > 0)
    {
        if(b & 1)
            res = (res * a) % m;
        a = (a * a) % m;
        b >>= 1;
    }
    return res;
}


void printLastdigit(ll a, ll b, ll k)
{
    ll tmp = binpow(a, b, k);
        printf("%03lld", tmp);
        //cout << "..."<< tmp<<endl;
}


int main()
{
    ///*
    //double start_time = clock();
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
    freopen("error.txt", "w", stderr);
#endif
    //*/

    int t;
    cin >> t;
    while(t--)
    {
        ll x, y, m;
        cin >> x >> y;
        m = 1000;
        double a = y * log10(x);
        double b = floor(pow(10, a - floor(a) + 3 - 1) ) ;
        cout << b << "...";
        printLastdigit(x, y, m);
        cout << endl;
    }

    //double end_time = clock();
    //printf( "Time = %lf ms\n", ( (end_time - start_time) / CLOCKS_PER_SEC)*1000);

    return 0;
}