136 - Ugly numbers/136.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 main(){
  28     vector<long long> ugly;
  29     ugly.push_back(1);
  30
  31     priority_queue<long long, vector<long long>, greater<long long> > q;
  32     q.push(1);
  33
  34     while (ugly.size() < 1500) {
  35         long long v = q.top();
  36         q.pop();
  37         if (ugly.back() != v) {
  38             ugly.push_back(v);
  39         }
  40         if (v % 3 != 0 and v % 5 != 0) {
  41             q.push(v * 2);
  42         }
  43
  44         if (v % 5 != 0) {
  45             q.push(v * 3);
  46         }
  47         q.push(v * 5);
  48     }
  49     // for (int i = 0; i < 100; ++i) {
  50     //     printf("ugly[%d] = %lld\n", i, ugly[i]);
  51     // }
  52     printf("The 1500'th ugly number is %lld.\n", ugly[1499]);
  53
  54     return 0;
  55 }