# UVa 136 Ugly Numbers (priority queue)

Source: Internet
Author: User

The number of test instructions may only have 2,3,5 numbers called the ugly number output 1500th ugly number

STL Excellent Queue Application 1 is the ugly number of ugly number 2,3,5 times are ugly number with priority queue simulation on the line

`#include <cstdio> #include <cstring> #include <set> #include <queue>using namespace Std;typedef  Long long ll;//priority_queue<ll, vector<ll>, greater<ll> > Q;struct cmp{    bool Operator () (ll A, LL b)    {return a > B;}}; Priority_queue<ll, Vector<ll>, cmp> q;set<ll> cnt;int ugly[3] = {2, 3, 5};int main () {    ll A, B;    Q.push (1);    Cnt.insert (1);    for (int i = 1;; ++i)    {        a = Q.top ();        Q.pop ();        if (i = =) break;        for (int j = 0; j < 3; ++j)        {            b = a * ugly[j];            if (!cnt.count (b))                Cnt.insert (b), Q.push (b);        }    }    printf ("The" th ugly number is%lld.\n ", a);    return 0;}`

 Ugly Numbers

Ugly numbers is numbers whose only prime factors is 2, 3 or 5. The sequence

1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, ...

Shows the first one ugly numbers. By convention, 1 is included.

Write a program to find and print the "th ugly number."

Input and Output

There is no. input to the program. Output should consist of a single line as shown below, with <number> replaced by the number computed.

Sample Output

The "th ugly number is <number>.

UVa 136 Ugly Numbers (priority queue)

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