백준 3190번 뱀 ( C++ )

문제

https://www.acmicpc.net/problem/3190

 

해설

간단한 조건의 길찾기 문제

 

코드

#include<iostream>
#include<algorithm>
#include<queue>
 
 
using namespace std;
//방향 => 오른쪽 +1 왼쪽 -1
int dx[4] = {1,0,-1,0};
int dy[4] = {0,1,0,-1};
int n,k,l,turn[10104],mp[104][104],ret = 0;
 
void go(){
  queue<pair<int,int>> q;
  q.push({0,0});
  mp[0][0] = -1;
  int len = 1;
  int direc = 0;
  int x=0,y=0;
  while(true){
    ret++;
    x = x + dx[direc];
    y = y + dy[direc];
    if(x>=0&&x<n&&y>=0&&y<n){
      if(mp[y][x]==0){
        q.push({y,x});
        int tmpx = q.front().second,tmpy = q.front().first;
        q.pop();
        mp[tmpy][tmpx] = 0;
      }
      else if(mp[y][x] == 1){
        q.push({y,x});
      }
      else{
        break;
      }
      mp[y][x] = -1;
    }
    else{
      break;
    }
    direc = ((direc + turn[ret]))%4;
    if(direc<0) direc+=4;
  }
}
 
 
int main(){ 
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);cout.tie(NULL);
 
  cin >> n >> k;
  int x=0,y=0;
  for(int i=0;i<k;i++){
    cin >> y >>x;
    mp[y-1][x-1] = 1;
  }
  
  cin >> l;
  int t=0;
  char direc = ' ';
  for(int i=0;i<l;i++){
    cin >> t >> direc;
    if(direc == 'D'){
      turn[t] = 1;
    }
    else{
      turn[t] = -1;
    }
  }
 
  go();
  cout << ret;
  return 0;
}