POJ 1061

/* * poj_1061.c * accepted * refer to: http://www.cnblogs.com/comeon4mydream/archive/2011/07/18/2109060.html */#include <stdio.h>typedef long long int int64;static int64 extGcd (int64 a, int64 b, int64 * p, int64 * q);static void poj_1061 ();int64 ret,tmp;int64 x, y, m, n, L;int64 p, q, r, n_gcd;int main (int argc, char * argv[]){poj_1061 ();return 0;}static void poj_1061 (){scanf ("%lld%lld%lld%lld%lld", &x, &y, &m, &n, &L); /* 注意long long int 的输入需要两个l作用d */n_gcd = extGcd(n-m, L, &p, &q);r = L/n_gcd;if ((x-y)%n_gcd){printf ("Impossible\n");}else{printf ("%lld\n",((x - y)/n_gcd * p % r + r ) % r); /* 输出也是需要ll修饰d */}}static int64 extGcd (int64 a, int64 b, int64 * p, int64 * q){if (!b){*p = 1; *q = 0; return a;}ret = extGcd (b, a%b, p, q);tmp = *p - a/b*(*q); *p = *q; *q = tmp;return ret;}