STL中的next_permutation用于将[first,last]范围内的元素重新排列到下一个字典上更大的排列。排列是N的每一个!元素可以采取的可能安排。这是C ++程序,用于在STL中实现Next_permutation。
Begin Define one integer array variable elements[]. Get the number of data e from the user. Initialize the array elements[] with e number of data from the keyboard. Sort all the array elements. do show(elements, e) //to display the current content of the array while (next_permutation(elements, elements + e)) End
#include<iostream> #include <algorithm> using namespace std; void show(int a[], int n) { for(int i = 0; i < n; i++) { cout<<a[i]<<" "; } cout<<endl; } int main () { int e, i; cout<<"Enter number of elements to be inserted: "; cin>>e; int elements[e]; for (i = 0; i < e; i++) { cout<<"Enter "<<i + 1<<" element: "; cin>>elements[i]; } sort (elements, elements + e); cout << "The "<<e<<"! possible permutations with "; cout<<e<<" elements: "<<endl; do { show(elements, e); } while (next_permutation(elements, elements + e)); return 0; }
输出结果
Enter number of elements to be inserted: 4 Enter 1 element: 7 Enter 2 element: 6 Enter 3 element: 2 Enter 4 element: 10 The 4! possible permutations with 4 elements: 2 6 7 10 2 6 10 7 2 7 6 10 2 7 10 6 2 10 6 7 2 10 7 6 6 2 7 10 6 2 10 7 6 7 2 10 6 7 10 2 6 10 2 7 6 10 7 2 7 2 6 10 7 2 10 6 7 6 2 10 7 6 10 2 7 10 2 6 7 10 6 2 10 2 6 7 10 2 7 6 10 6 2 7 10 6 7 2 10 7 2 6 10 7 6 2