The 3n + 1 problem -题解(C语言代码)

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#include<stdio.h>
#include<math.h>
int is(int n)
{
    if(n==1) return 1;
    if(n%2) n=3*n+1;
    else n=n/2;
    return is(n)+1;
}
int main()
{
    int i,j;
    while(scanf("%d%d",&i,&j)!=EOF)
    {
        int k,t,x=0;
        if(i>j) k=j;
        else k=i;
        for(;k<=((j+i)+abs(j-i))/2;k++)//max(i,j)=((j+i)+abs(j-i))/2;
        {
            t=is(k);
            if(x<t) x=t;
        }
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        printf("%d %d %d\n",i,j,x);
    }
    return 0;   
}