标签：style blog http color io os ar strong for
Uva 11889 - Benefit（ 数论 ）
题意:
calculate the lowest integer B such that LCM(A, B) = C
分析:
LCM(A,B) = C = A*B/GCD(A,B)
C*GCD(A,B) = A*B
C/A = B/GCD(A,B)
如果C%A != 0 无解
否则, 令t = C/A
B = t * GCD(A,B) 即B 一定是 t 的整数倍
从t开始枚举B
#include <cstdio> typedef long long LL; typedef unsigned long long ULL; ULL gcd(ULL a,ULL b) { return b == 0 ? a : gcd(b, a%b); } void Orz() { LL A, C, T; scanf("%d",&T); while(T--) { scanf("%lld %lld",&A,&C); int flag = 1; if(C % A == 0) { LL t = C/A; for(int B = t;B <= C; B += t) { if(B/gcd(B,A) == t) { flag = 0; printf("%lld\n",B); break; } } } if(flag) puts("NO SOLUTION"); } } int main() { Orz(); return 0; }
标签：style blog http color io os ar strong for
原文地址：http://www.cnblogs.com/BigBallon/p/3995863.html
