codevs3990：中国剩余定理2

好久没做codevs啦

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<vector>
 6 #define MAXN 100000+10
 7 #define ll long long
 8 #define pb push_back
 9 #define ft first
10 #define sc second
11 #define mp make_pair
12 using namespace std;
13 ll M=1LL,X;
14 ll c[15],m[15];
15 int n;
16 void extgcd(ll a,ll b,ll &x,ll &y){
17     if(!b){
18         x=1,y=0;
19     }
20     else{
21         ll xx,yy;
22         extgcd(b,a%b,xx,yy);
23         x=yy,y=xx-a/b*yy;
24     }
25 }
26 ll Inv(ll x,ll p){
27     //(x,p)=1
28     ll a,b;
29     extgcd(x,p,a,b);
30     return (a%p+p)%p;
31 }
32 ll a,b;
33 int main()
34 {
35 
36     scanf("%d%lld%lld",&n,&a,&b);
37     for(int i=1;i<=n;i++){
38         scanf("%lld%lld",&m[i],&c[i]);
39         M*=m[i];
40     }
41     for(int i=1;i<=n;i++){
42         X+=c[i]*M/m[i]*Inv(M/m[i],m[i]);
43     }
44     X%=M;
45     ll s=(a-X)/M-5;
46     while(X+s*M<a)s++;
47     ll t=(b-X)/M+5;
48     while(X+t*M>b)t--;
49     ll ans=t-s+1;
50     printf("%lld\n%lld\n",ans,(ans?X+M*s:0LL));
51     return 0;
52 }

 

posted @ 2018-01-19 11:30  white_hat_hacker  阅读(173)  评论(0)  编辑  收藏  举报