UVA 10407 差分思想的运用

就是每两项相减，肯定能被模数整除。

 #include <iostream>
 #include <cstring>
 #include <cstdio>
 #include <algorithm>
 using namespace std;

 const int Maxn=;
 int f[Maxn],n,Ans;
 int Gcd(int a,int b) {if (b==) return a; return Gcd(b,a%b);}
 inline int Abs(int x) {return x>?x:-x;}
 int main()
 {
     while (true)
     {
         n=;
         scanf("%d",&f[++n]);
         if (f[n]==) break;
         while (f[n]!=) scanf("%d",&f[++n]);
         n--;
         for (int i=;i<n;i++)
             f[i]=f[i]-f[i+];
         Ans=f[];
         for (int i=;i<n;i++)
             Ans=Gcd(f[i]==?Ans:f[i],Ans);
         printf("%d\n",Abs(Ans));
     }
     return ;
 }

C++