11029 - Leading and Trailing
Topic: Binary Exponentiation
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///Binary Exponentiation | |
#include <bits/stdc++.h> | |
using namespace std; | |
#define INF 1<<30 | |
#define MAX 10005 | |
#define FASTIO ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0); | |
typedef long long ll; | |
// compute x^n mod m | |
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() | |
{ | |
//FASTIO | |
///* | |
//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; | |
} |
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