UVa/100 - The 3n + 1 problem/100.cpp

   1 using namespace std;
   2 #include <algorithm>
   3 #include <iostream>
   4 #include <iterator>
   5 #include <numeric>
   6 #include <sstream>
   7 #include <fstream>
   8 #include <cassert>
   9 #include <climits>
  10 #include <cstdlib>
  11 #include <cstring>
  12 #include <string>
  13 #include <cstdio>
  14 #include <vector>
  15 #include <cmath>
  16 #include <queue>
  17 #include <deque>
  18 #include <stack>
  19 #include <list>
  20 #include <map>
  21 #include <set>
  22
  23 #define foreach(x, v) for (typeof (v).begin() x=(v).begin(); x !=(v).end(); ++x)
  24 #define For(i, a, b) for (int i=(a); i<(b); ++i)
  25 #define D(x) cout << #x " is " << x << endl
  26
  27 int f(unsigned int n) {
  28     int ans = 0;
  29     while (n > 1) {
  30         ans++;
  31         if (n % 2 == 0) n = n / 2;
  32         else n = 3 * n + 1;
  33     }
  34     return ans + 1;
  35 }
  36
  37 int main(){
  38     unsigned int a, b;
  39     while (cin >> a >> b) {
  40         int ans = -1;
  41         for (int i = min(a, b); i <= max(a, b); ++i) {
  42             ans = max(ans, f(i));
  43         }
  44         printf("%d %d %d\n", a, b, ans);
  45     }
  46     return 0;
  47 }