【排队买票】 （Java代码）

解题思路:

全排列



注意事项:




参考代码:

import java.util.Scanner;

public class Main {

static int k=0;

public static void main(String[] args) {

Scanner input =new Scanner(System.in);

int M=input.nextInt();

int N=input.nextInt();

int K=input.nextInt();

int [] a=new int [11];

bainhao(a,M,N);

quanpailie(a,0,M);

}

public static void bainhao(int [] a,int M,int N){

int i=0;

for(;i<M;i++){

if(i<N)a[i]=1;

else a[i]=2;

}

}

public static void quanpailie(int []a,int low,int leng){

int i,t=0;

if(low==leng){

k+=panduan(a,leng);

}

for(i=low;i<leng;i++){

t=a[low];

a[low]=a[i];

a[i]=t;

quanpailie(a,low+1,leng);

t=a[low];

a[low]=a[i];

a[i]=t;

}

if(low==0)System.out.println(k);

}

public static int  panduan(int [] a,int n ){

int i,Shoupiao_yuan=0;

for(i=0;i<n;i++){

if(a[i]==1)Shoupiao_yuan++;

else Shoupiao_yuan--;

if(Shoupiao_yuan<0)break;

}

if(Shoupiao_yuan>=0)return 1;

else return 0;

}

}