#include <stdio.h> 
#include <stdlib.h> 
#include <iostream> 
 
using namespace std;
 
int main() {
	int number = 0 ;
	int temp1 = 0 ;
	int temp2 = 0 ;
	int temp3 = 1 ;
	int x = 0 ;
	int y = 1 ;
	int z = 0 ;
	int a[x];  // 待使用者輸入數字後再決定長度 
	int b[z];
 
	printf("Please enter a number: ");
	cin >> number ; // 讀入數字
 
	temp1 = number ;
	while ( x < temp1) {
		a[x]= y ;
		x++;
		y++;
		// 開始產生陣列, 長度為使用者輸入之數字
		// 例如: 輸入5則 a[0] = 1, a[1]=2, ..., a[4]=5; 
	}
 
	while( temp1 > 0 ) {
		temp3 = temp3 *temp1 ;
		temp1 = temp1 -1 ; //求出幾種排列 例: 輸入5則有5*4*3*2*1種排列. 
	}
 
	temp2 = temp3/number; // 每個數字開頭有幾個 例: 輸入5則每個數字開頭有24種排列, 總共120種排列 
	printf("%d", temp2);
 
 
}

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

NQ==

5