快速幂 E - Leading and Trailing LightOJ - 1282

 1 #include <iostream>
 2 #include <cstring>
 3 #include <string>
 4 #include <map>
 5 #include <set>
 6 #include <algorithm>
 7 #include <fstream>
 8 #include <cstdio>
 9 #include <cmath>
10 #include <stack>
11 #include <queue>
12 using namespace std;
13 const double Pi=3.14159265358979323846;
14 typedef long long ll;
15 const int MAXN=5000+5;
16 const int dx[5]={0,0,0,1,-1};
17 const int dy[5]={1,-1,0,0,0};
18 const int INF = 0x3f3f3f3f;
19 const int NINF = 0xc0c0c0c0;
20 ll mod_pow(ll n,ll x,ll mod)
21 { 
22     ll ans=1;
23     while(n>0){
24         if(n&1) ans=ans*x%mod;
25         x=x*x%mod;
26         n>>=1;
27     }
28     return ans;
29 }
30 
31 int main()
32 {
33     int cnt=0;
34     int t;cin>>t;
35     while(t--)
36     {
37         ll n,k;cin>>n>>k;
38         ll last=mod_pow(k,n,1000);        
39         double p=k*log10(n);
40         ll x=(ll)p;double y=p-x;
41         y=pow(10,y)*100;
42         ll first=int(y);
43         printf("Case %d: %03lld %03lld\n",++cnt,first,last);
44     }
45     return 0; 
46  }