1096.Consecutive Factors（20）

テーマリンク:http://www.patest.cn/contests/pat-a-practise/1096
タイトル:
Among all the factors of a positive integer N、there may exist several consecutive numbers.For example、630 can be factored as 3*5*6*7、where 5、6、and 7 are the three consecutitive numbebers.Novevevevevevevevevevevevevevevevevevevevevevevevevevevevevetititititytytytytytytytytytytypopopopopopopopopopopopopopopoints.inininininininininininininininininininininininininininininininininininininquence of the consecutive factors.
Input Specification:
Each input file contains one test case，which gives the integer N（1＜N＜231）.
Output Specification:
For each test case，print in the first line the maximnumber of consecutive factors.The n in the second line，print the smalest sequence of the consecutive factors in the format「factor[1]*factor[2]the factor」
Sample Input:

630

Sample Output:

3
5*6*7

分析:
題目はすべての連乗の因数の中で一番長い列を探します。ここはすべての因数に遍歴するのではなく、積に与えられた数の中で探すのです。例えば12、一番長いのは2、3*4で、3*3*4ではなくて、2*3*4です。
参考資料：
http://www.cnblogs.com/asinlzm/p/4460935.html
ACコード:

#include<cstdio>
#include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<stack>
#include<string>
#include<string.h>
#include<map>
#include<cmath>
using namespace std;
int main(){
 //freopen("F://Temp/input.txt", "r", stdin);
 int N = 0;
 cin >> N;
 if (N == 2 || N == 3 || N == 5)  { printf("1
%d", N); return 0; }
 int num = (int)sqrt(N), len = 0, factors[1000000] = { 0 };
 for (int i = 2; i <= num; i++)  if (N%i == 0) factors[len] = i, len++;
 factors[len] = N, len++;
 int maxlen = 0, maxfactor = N;
 int templen = 0, tempfactor = 0;
 for (int i = 0; i<len; i++){//   
  num = N, tempfactor = factors[i], templen = 0;
  while (num%tempfactor == 0) templen++, num /= tempfactor, tempfactor++;
  if (templen>maxlen) maxlen = templen, maxfactor = factors[i];<span style="font-family:     ; font-size: 14px; widows: auto;">//                 </span>
 }
 printf("%d
", maxlen);
 for (int i = 0; i<maxlen; i++)
 {
  if (i)  printf("*%d", maxfactor);//            
  else  printf("%d", maxfactor);
  maxfactor++;
 }
 printf("
");
 return 0;
}

スクリーンショット:
——アプリ陳小旭