poj3278 已到简单bfs

#include <iostream>
using namespace std;

int visited[100001];
int a[100001];
int que[100001];
int move[3][2] = {{1,-1},{1,1},{2,0}};

int main()
{
    int n,k;
    cin>>n>>k;
    int front,rear,temp;
    int next;
    front = 0;
    rear = 1;
    a[front] = n;
    memset(visited,0,sizeof(visited));
    memset(que,0,sizeof(que));
    visited[n] = 1;
    if(n>k){cout<<n-k<<endl;}
    else
    {
        while(front<rear)
        {
              temp = front++;
              if(a[temp]==k){cout<<que[k]<<endl;break;}
              for(int i=0;i<3;i++)
              {
                      next = a[temp]*move[i][0]+move[i][1];
                      if(next>=0 && next<=100000 && !visited[next])
                      {
                                 visited[next] = 1;
                                 que[next] = que[a[temp]] + 1;
                                 a[rear++] = next;
                      }
              }
        }
    }
    
    system("pause");
}