HDU 1035 Robot Motion

Posted lovelcy

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了HDU 1035 Robot Motion相关的知识,希望对你有一定的参考价值。

Robot Motion

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 3466    Accepted Submission(s): 1608


Problem Description
技术图片

A robot has been programmed to follow the instructions in its path. Instructions for the next direction the robot is to move are laid down in a grid. The possible instructions are 

N north (up the page)
S south (down the page)
E east (to the right on the page)
W west (to the left on the page)

For example, suppose the robot starts on the north (top) side of Grid 1 and starts south (down). The path the robot follows is shown. The robot goes through 10 instructions in the grid before leaving the grid.

Compare what happens in Grid 2: the robot goes through 3 instructions only once, and then starts a loop through 8 instructions, and never exits.

You are to write a program that determines how long it takes a robot to get out of the grid or how the robot loops around.
 

 

Input
There will be one or more grids for robots to navigate. The data for each is in the following form. On the first line are three integers separated by blanks: the number of rows in the grid, the number of columns in the grid, and the number of the column in which the robot enters from the north. The possible entry columns are numbered starting with one at the left. Then come the rows of the direction instructions. Each grid will have at least one and at most 10 rows and columns of instructions. The lines of instructions contain only the characters N, S, E, or W with no blanks. The end of input is indicated by a row containing 0 0 0.
 

 

Output
For each grid in the input there is one line of output. Either the robot follows a certain number of instructions and exits the grid on any one the four sides or else the robot follows the instructions on a certain number of locations once, and then the instructions on some number of locations repeatedly. The sample input below corresponds to the two grids above and illustrates the two forms of output. The word "step" is always immediately followed by "(s)" whether or not the number before it is 1.
 

 

Sample Input
3 6 5
NEESWE
WWWESS
SNWWWW
4 5 1
SESWE
EESNW
NWEEN
EWSEN
0 0
 

 

Sample Output
10 step(s) to exit 3 step(s) before a loop of 8 step(s)
 

 

Source
 
 
解题思路:
按照数组的值走,一步一步模拟,vis[][]储存机器人的步数。
 
AC代码:
#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int  step=0,row,col,start,flag=0;
char map[20][20];
int vis[20][20];
void search(int x,int y,int step)
{
    if(flag)
        return;
    if(vis[x][y]){
        int cnt=vis[x][y];
        printf("%d step(s) before a loop of %d step(s)
",cnt-1,step-cnt);
        flag=1;
        return;
    }
    if(x==0||y==0||x>row||y>col){
        printf("%d step(s) to exit
",step-1);
        return;
        flag=1;
    }
    vis[x][y]=step;
    if(map[x][y]==N)//n
        search(x-1,y,step+1);
    else if(map[x][y]==S)//s
        search(x+1,y,step+1);
    else if(map[x][y]==W)//w
        search(x,y-1,step+1);
    else if(map[x][y]==E)//e
        search(x,y+1,step+1);
}
int main()
{
    while(cin>>row>>col>>start){
        memset(vis,0,sizeof vis);
        if(row==0&&col==0&&start==0)
            break;
        for(int i=1;i<=row;i++){
            for(int j=1;j<=col;j++){
                cin>>map[i][j];    
            }
        }
        flag=0;
        search(1,start,1);
    }
    return 0;
} 

 

以上是关于HDU 1035 Robot Motion的主要内容,如果未能解决你的问题,请参考以下文章

HDU 1035 [Robot Motion] 模拟 记忆

HDU 1035

hdu-1573 Robot Motion

POJ1573 ZOJ1708 UVA10116 UVALive5334 HDU1035 Robot MotionDFS+BFS

POJ 1573 Robot Motion

N - Robot Motion(第二季水)