hdu1576A/B

解题思路：求乘法逆元就好了。

 1 //Accepted    228 KB    0 ms

 2 #include <cstdio>

 3 #include <cstring>

 4 const int pp = 9973;

 5 int extend_euclid(int a,int b,int &x,int &y)

 6 {

 7     if (b==0)

 8     {

 9         x=1;

10         y=0;

11         return a;

12     }

13     int d=extend_euclid(b,a%b,x,y);

14     int t=x;

15     x=y;

16     y=t-a/b*y;

17     return d;

18 }

19 int A,B;

20 int a,b,x,y;

21 void slove()

22 {

23     a=B;

24     b=pp;

25     extend_euclid(a,b,x,y);

26     x=(x%b+b)%b;

27     int ans=A*x%pp;

28     printf("%d\n",ans);

29 }

30 int main()

31 {

32     int T;

33     scanf("%d",&T);

34     while (T--)

35     {

36         scanf("%d%d",&A,&B);

37         slove();

38     }

39     return 0;

40 }