MOONOJ1052 factorial problem solution cycle entry title

Description [title]

Enter a number n, you need to output n!.

! N where n represents a factorial, namely:! N = n * (n-1) * ... * 1.

For example, 5! = 4 * 5 * 3 * 2 * 1 = 120.

[Input Format]

Only one input integer n (1 <= n <= 10).

[Output format]

Output "scared I picked up the holding (n times) My little carp I (n times)." The results per line.

[Sample input]

5

[Sample output]

120

Sample [explain]

Here we enter 5, then our output is 5! , I.e., 120.

[Data] scale

50% of the data satisfies 1≤n≤5;

100% data satisfy 1≤n≤10.

[Analysis] title

This question is an entry-cycle problem, we only need to set a variable n, initially n == 1, then open a for loop, once let n multiplied by 2,3, ..., n will be able to get the final the results.

We can use the recursive way to write.

#include <bits/stdc++.h>
using namespace std;
int n, ans = 1;
int main() {
    cin >> n;
    for (int i = 1; i <= n; i ++) ans *= i;
    cout << ans << endl;
    return 0;
}

It can also be used recursively to complete. Here we func (int x) for returning x !:

#include <bits/stdc++.h>
using namespace std;
int n, ans = 1;

int func(int x) {
    if (x == 1) return 1;
    return x * func(x-1);
}

int main() {
    cin >> n;
    cout << func(n) << endl;
    return 0;
}