hdu5878 I Count Two Three（二分+ 打表）

 1 #include<cstdio>
 2 #include<algorithm>
 3 using namespace std;
 4 typedef long long ll;
 5 const int N = 1e9;
 6 ll s[10000];
 7 ll pow(ll a, ll b){
 8     ll r = 1;
 9     while(b){
10         if(b & 1)
11             r *= a;
12         a *= a;
13         b >>= 1;
14     }
15     return r;
16 }
17 int cnt;
18 void init(){
19     ll i, j, k ,l, t;
20     cnt = 0;
21     for(i = 0; i < 31; ++i){
22         for(j = 0; j < 20 ; ++j){
23             for(k = 0 ;k < 14 ; ++k){
24                 for(l = 0; l < 12; ++l){
25                     t = pow(2, i) * pow(3, j);
26                     if(t > 1e9)
27                         break;
28                     t *= pow(5, k);
29                     if(t > 1e9)
30                         break;
31                     t *=pow(7, l);
32                     if(t > 1e9)
33                         break;
34                     s[cnt++] = t;
35                 }
36             }
37         }
38     }
39     sort(s, s + cnt);
40 }
41 void bi_search(int n){
42     int l = 0,r = cnt - 1;
43     while(l < r){
44         int mid = l + (r - l)/2;
45         if(s[mid] >= n)
46             r = mid;
47         else
48             l = mid + 1;
49     }
50     printf("%I64d\n", s[l]);
51 }
52 int main(){
53     int t, n;
54     scanf("%d", &t);
55     init();
56     while(t--){
57         scanf("%d", &n);
58         bi_search(n);
59     }
60     return 0;
61 }