全排列

一种全排列是将n个数字放入n个位置里，一种是n个位置上任意位置都可以取0，1，2，...，m，位置之间没有约束

#include <iostream>
using namespace std;
void permutation(char *pStr, char *pBegin, int &count){
    if (*pBegin == ''){
        printf("%s	", pStr);
        count++;
    }else{
        for (char *pCh = pBegin; *pCh != ''; ++pCh){
            
                char temp1 = *pCh;
                *pCh = *pBegin;
                *pBegin = temp1;
            
            permutation(pStr, pBegin + 1,count);
            
                temp1 = *pCh;
                *pCh = *pBegin;
                *pBegin = temp1;
            
        }
    }

}
int main(){
    char pS[] = "123456";
    int count = 0;
    permutation(pS, pS, count);
    printf("%d", count);
    system("pause");
}
//一种是n个位置上任意位置都可以取0，1，2，...，m，位置之间没有约束
#include <iostream>
using namespace std;
void permutation(char *pStr, char *pBegin, int &count){
        if (*pBegin == ''){
            printf("%s	", pStr);
            count++;
        }else{
            for (int i = 0; i < 10;i++){
                
                *pBegin = i + '0';
                
                permutation(pStr, pBegin + 1,count);
                
                
            
            }
        }
    
}
int main(){
    const int n = 3;
    int count = 0;
    char *pStr = new char[n+1];
    pStr[n] = '';
    pStr[0] = pStr[1] = pStr[2] = '0';
    permutation(pStr, pStr, count);
    printf("%d
", count);
    delete[]pStr;
    system("pause");
}