目录
题目:
Find Integer
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 117 Accepted Submission(s): 49
Special Judge
Problem Description
people in USSS love math very much, and there is a famous math problem .
give you two integers n,a,you are required to find 2 integers b,c such that an+bn=cn.
Input
one line contains one integer T;(1≤T≤1000000)
next T lines contains two integers n,a;(0≤n≤1000,000,000,3≤a≤40000)
Output
print two integers b,c if b,c exits;(1≤b,c≤1000,000,000);
else print two integers -1 -1 instead.
Sample Input
1
2 3
Sample Output
4 5
题意:
给出中的a,n求b,c的任一组解,不存在输出-1 -1
思路:
通过费马定理可以得出n>2和n=0时,是无解的,然后n=2通过对奇偶性的讨论,我们可以很轻易的得出b和c的一组解。满足
AC代码:
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
ll a,b,c,d,n;
int main()
{
int t;
scanf("%d",&t);
while(t--){
scanf("%lld%lld",&n,&a);
if(n > 2) printf("-1 -1\n");
else if(n == 0) printf("-1 -1\n");
else if(n == 1) printf("1 %lld\n",a + 1);
else if(n == 2){
b = a & 1 ? (a - 1) * (a - 1) / 2 + a - 1 : a * a / 4 - 1;
c = a & 1 ? (a - 1) * (a - 1) / 2 + a : a * a / 4 + 1;
printf("%lld %lld\n",b,c);
}
}
return 0;
}