HDOJ 1035 模拟 水

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=1035

稍微有点复杂，但是只要模拟出来应该就能过了。

#include <iostream>
using namespace std;

class node
{
public:
    char instruct;
    int stepId;
};

const int SIZE = 12;
char aLine[SIZE];
node map[SIZE][SIZE];

void move(int &curRow,int &curCol,char instruct)
{
    switch (instruct)
    {
    case 'N':
        curRow --;
        break;
    case 'S':
        curRow ++;
        break;
    case 'W':
        curCol --;
        break;
    case 'E':
        curCol ++;
        break;
    }
}

//计算从起始点(1,initCol)走到(endRow,endCol)需要走多个步
int countStepBeforeExit(int initCol,int endRow,int endCol)
{
    int curRow = 1,curCol = initCol;
    int stepBeforeExit = 0;
    while (1)
    {
        if (curRow == endRow && curCol == endCol)
            break;
        stepBeforeExit ++;
        move(curRow,curCol,map[curRow][curCol].instruct);
    }
    return stepBeforeExit;
}

//判断(curRow,curCol)是否出界
int judgeExit(int curRow,int curCol,int row,int col)
{
    if (curRow < 1 || curRow > row || curCol < 1 || curCol > col)
        return 1;
    return 0;
}

int main ()
{
    int row,col,initCol;
    while (scanf("%d%d%d",&row,&col,&initCol) != -1)
    {
        if (row == 0 && col == 0 && initCol == 0)
            break;
        //初始化
        for (int i = 0;i < SIZE;i ++)
            for (int j = 0;j < SIZE;j ++)
                map[i][j].stepId = 0;
        for (int i = 1;i <= row;i ++)
        {
            scanf("%s",aLine);
            for (int j = 1;j <= col;j ++)
            {
                map[i][j].instruct = aLine[j - 1];
            }
        }
        int isExit = 1,stepBeforeExit,stepLoop;
        int preRow,preCol;
        preRow = preCol = -1;
        int curRow = 1,curCol = initCol;
        int stepCount = 0;
        while (1)
        {
            //这一点之前曾走过，说明出现了回路
            if (map[curRow][curCol].stepId != 0)
            {
                stepLoop = map[preRow][preCol].stepId - map[curRow][curCol].stepId + 1;
                //计算走到当前点的前一点用了多少个step(s)
                stepBeforeExit = countStepBeforeExit(initCol,curRow,curCol);
                //最后没能走出去
                isExit = 0;
                break;
            }
            else if (judgeExit(curRow,curCol,row,col))
            {
                isExit = 1;
                stepBeforeExit = map[preRow][preCol].stepId;
                break;
            }
            stepCount ++;
            map[curRow][curCol].stepId = stepCount;
            preRow = curRow , preCol = curCol;
            //走到下一点
            move(curRow,curCol,map[curRow][curCol].instruct);    
        }
        //能走出去
        if (isExit)
            printf("%d step(s) to exit\n",stepBeforeExit);
        else
            printf("%d step(s) before a loop of %d step(s)\n",stepBeforeExit,stepLoop);
    }
    return 0;
}