UVa 10407 - Simple division

题目：给你几个数，求使他们同余的最大除数。

分析：数论。取其中两不相同数的差，差值一定是除数的倍数，利用差值枚举除数即可。

说明：小心都是素数的情况，被坑了╮(╯▽╰)╭。

#include <algorithm>#include <iostream>#include <cstdlib>#include <cstdio>#include <cmath>using namespace std;long long save[1001];int main(){int count;while (cin >> save[count=0] && save[count]) {count ++;while (cin >> save[count] && save[count])count ++;sort(save, save+count);int s = save[count-1]-save[0];for (int i = 1 ; i < count ; ++ i)if (save[i] > save[i-1] && save[i]-save[i-1] < s)s = save[i]-save[i-1];for (int i = 1 ; i <= s ; ++ i)if (s%i == 0) {int d = s/i,r = (save[0]%d+d)%d,flag = 1;for (int j = 1 ; j < count ; ++ j)if ((save[j]%d+d)%d != r) {flag = 0;break;}if (flag) {cout << d << endl;break;}}}return 0;}