UVa 694 - The Collatz Sequence

和3n+1类似，注意要用long long，int会TLE。

代码如下：

 

#include<stdio.h>
int main()
{
    long long n, m, term, i, num=1;
    scanf("%lld%lld", &n, &m);
    while(n>=0 || m>=0)
    {
        term=1;
        i=n;
        while(i<=m && i!=1)
        {
            if (i%2 == 0)
            {
                i/=2;
            }
            else
            {
                i=3*i+1;
                if (i>m)
                    break;
            }
            term++;
        }
        printf("Case %lld: A = %lld, limit = %lld, number of terms = %lld\n", num++, n, m, term);
        scanf("%lld%lld", &n, &m);
    }
    return 0;
}