1035 - Intelligent Factorial Factorization
Input
Given an integer N, you have to prime factorize N! (factorial N).
Input starts with an integer T (≤ 125), denoting the number of test cases.
Each case contains an integer N (2 ≤ N ≤ 100).
Output
For each case, print the case number and the factorization of the factorial in the following format as given in samples.
Case x: N = p1 (power of p1) * p2 (power of p2) * ...
Here x is the case number, p1, p2 ... are primes in ascending order.
Sample Input |
Output for Sample Input |
3236 | Case 1: 2 = 2 (1)Case 2: 3 = 2 (1) * 3 (1)Case 3: 6 = 2 (4) * 3 (2) * 5 (1) |
Notes
The output for the 3rd case is (if we replace space with '.') is
Case.3:.6.=.2.(4).*.3.(2).*.5.(1)
题目类型:素因子分解
算法分析:N!中有素数p的个数为[N/p] + [N/p^2] + [N/p^3] + …由于N不太大,可以先将100以内的素数都打出来,然后从小到大判断每一个素数及其倍数是否满足 N / p ^ k != 0,将结果累加,否则判断下一个素数或者是退出判断
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 |
#include <set> #include <bitset> #include <list> #include <map> #include <stack> #include <queue> #include <deque> #include <string> #include <vector> #include <ios> #include <iostream> #include <fstream> #include <sstream> #include <iomanip> #include <algorithm> #include <utility> #include <complex> #include <numeric> #include <functional> #include <cmath> #include <ctime> #include <climits> #include <cstdarg> #include <cstdio> #include <cstdlib> #include <cstring> #include <cctype> #include <cassert> #define lson rt << 1, l, m #define rson rt << 1 | 1, m + 1, r using namespace std; const int INF = 0x7FFFFFFF; const double EPS = 1e-10; const double PI = 2 * acos (0.0); const int MOD = 7; const int maxn = 100 + 66; bool prime[maxn]; void GetPrime () { memset (prime, true, sizeof (prime)); int i; for (i = 2; i < maxn; i++) { int j; for (j = 2; j * i < maxn; j++) prime[i*j] = false; } } int main() { // ifstream cin ("aaa.txt"); GetPrime (); int t, flag = 1; cin >> t; while (t--) { int n; cin >> n; cout << "Case " << flag++ << ": " << n << " = "; int i, sum; bool is_first = true; for (i = 2; i < maxn; i++) { if (prime[i]) { if (n / i == 0) break; sum = n / i; int temp = i; while (n / (temp * i)) { sum += n / (temp * i); temp *= i; } if (is_first) { is_first = false; cout << i << " " << "(" << sum << ")"; } else cout << " * " << i << " " << "(" << sum << ")"; } } cout << endl; } return 0; } |
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