HDU ACM 1019 Least Common Multiple

Least Common Multiple

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 18363    Accepted Submission(s): 6840

Problem Description

The least common multiple (LCM) of a set of positive integers is the smallest positive integer which is divisible by all the numbers in the set. For example, the LCM of 5, 7 and 15 is 105.

Input

Input will consist of multiple problem instances. The first line of the input will contain a single integer indicating the number of problem instances. Each instance will consist of a single line of the form m n1 n2 n3 ... nm where m is the number of integers in the set and n1 ... nm are the integers. All integers will be positive and lie within the range of a 32-bit integer.

 

Output

For each problem instance, output a single line containing the corresponding LCM. All results will lie in the range of a 32-bit integer.

Sample Input

2

3 5 7 15

6 4 10296 936 1287 792 1

 

Sample Output

105 10296

 

Source

East Central North America 2003, Practice

 

Recommend

JGShining

 

#include<stdio.h>
int main()
{
    int i, j, n, k, num, count = 1;
    int  ch, p1, r, q1, p, q;
    scanf("%d", &n);
    while(n--)
    {
        i = q = p = r = 0;
        count = 1;
        scanf("%d", &num);
        while(num--)
        { 
            scanf("%d", &ch);
            if(count++ == 1) {p = p1 = ch; continue;}
            else q = q1 = ch;
            if(q > p)
            {
                r = q; q = p;  p = r;
            }
            while(p%q != 0)
            {
                r = q;
                q = p%q;
                p = r;
                
            }
            p = p1 = p1/q*q1;
        }
        printf("%d\n", p);
    }
    return 0;
}

解题报告：

这题是我提交最多的一题，纠结在于不懂32-bit integer到底是什么意思，从一开始就没用int定义变量，最小公倍数 = 数之间相乘/数之间的最大公约数，思路无错，测试数据完全正确，但提交上去就不是一回事了，我用了long long，但总是WA，过段时间没辙了，discuss中找到了相似的代码，将我的代码一点一点的插入他人的代码中，一直提交着，我要看看哪里出错了，求最大公约数没错——大小数替换没错，最后干脆把注释的内容都删掉了，提交还是错误，无奈之下将所有的数改为int型，AC了！我只知道数的范围开小了会WA，但没想到开大了也会WA!