Sicily.1293 3n+1数链问题

len函数计算特定值的数链长。循环比较找到最大值即可。

代码如下：

#include <iostream>using namespace std;int len(int k){int len = 1;if (k == 1)return len;while(k != 1){if (k % 2)k = 3 * k + 1;elsek = k / 2;len ++;}return len;}int main(){int i,j;cin >> i >> j;int max = 0;for (int k = i;k <= j;k ++){int tem = len(k);if (max < tem)max = tem;}cout << max << endl;}