练习2 - 奇怪的电梯

#include <iostream>
#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<math.h>
#include<sstream>
using namespace std;
#define L 101
const int N=5,A=1,B=5;
int a[N+1]={0,3,3,1,2,5};
int head=0,tail=1;	//tail指向空白 
//j<m时		f[i][j] = f[i-1][K+j-m] + a[i];
int g[N+1]={0};	//占位;
struct line{
	int c;	//楼层 
	int s=0;	//次数 
}b[L];	//模仿队列 
int c=0;
bool flag=false;
int main()
{	
	//初始化队列
	b[head].c = A; 
	g[A]=1;
	while(head<tail){
		head++;
		c = b[head-1].c;
		if(c==B){
			flag = true;
			cout << b[head-1].s;
			break;
		}
		if(c+a[c] <= N && !g[c+a[c]]){	//可以向上走 
			g[c+a[c]] = 1;	//先占领后发展 
			b[tail].c = c+a[c];
			b[tail].s = b[head-1].s+1;
			tail++;
		}
		if(c-a[c] >=1 && !g[c-a[c]]){
			g[c-a[c]] = 1;	//先占领后发展 
			b[tail].c = c-a[c];
			b[tail].s = b[head-1].s+1;
			tail++;
		}	
	}
	if(!flag)cout << -1;
	return 0;
}
//cout << "输入："

结果：