[PS][시뮬레이션][순환시키기]/[BOJ][17144][미세먼지 안녕!]

boj17144.cpp

#include <iostream>
#include <string.h>
using namespace std;

int n,m,t;
int map[51][51];
int dust[51][51];
pair<int, int> u = { -1,-1 };
pair<int, int> d = { -1,-1 };

int dx[] = { 0,0,1,-1 };
int dy[] = { 1,-1,0,0 };

void getInput(void) {
	cin >> n >> m >> t;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			cin >> map[i][j];
			if (map[i][j] == -1) {
				if (u.first == -1) {
					u.first = i;
					u.second = j;
				}
				else {
					d.first = i;
					u.second = j;
				}
			}
		}
	}
}

bool inRange(int x, int y) {
	return 0 <= x && 0 <= y && x < n && y < m && map[x][y] != -1;
}

void solve(void) {
	int s,i,j,k;
	int nx, ny;
	int cnt, ans = 0;
	for (s= 0; s < t; s++) {
		//확산
		for (i = 0; i < n; i++) {
			for (j = 0; j < m; j++) {
				if (map[i][j]) {
					cnt = 0;
					for (k = 0; k < 4; k++) {
						nx = i + dx[k];
						ny = j + dy[k];
						if (!inRange(nx, ny)) continue;
						cnt++;
						dust[nx][ny] += map[i][j] / 5;
					}
					map[i][j] -= (cnt * (map[i][j] / 5));
				}
			}
		}
		for (i = 0; i < n; i++) for (j = 0; j < m; j++) {
			map[i][j] += dust[i][j];
			dust[i][j] = 0;
		}
		//바람불기
		for (i = u.first - 1; i >= 1; i--) map[i][0] = map[i - 1][0];
		for (j = 0; j <= m - 2; j++) map[0][j] = map[0][j + 1];
		for (i = 0; i <= u.first - 1; i++) map[i][m - 1] = map[i + 1][m - 1];
		for (j = m - 1; j >= 1; j--) map[u.first][j] = map[u.first][j - 1];
		map[u.first][1] = 0;
		for (i = d.first + 1; i <= n - 2; i++) map[i][0] = map[i + 1][0];
		for (j = 0; j <= m - 2; j++) map[n-1][j] = map[n-1][j + 1];
		for (i = n - 1; i >= d.first+1; i--) map[i][m - 1] = map[i - 1][m - 1];
		for (j = m - 1; j >= 1; j--) map[d.first][j] = map[d.first][j - 1];
		map[d.first][1] = 0;
		
	}
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < m; j++) {
			if (map[i][j] > 0) ans += map[i][j];
		}
	}
	cout << ans << "\n";
}

int main(void) {
	getInput();
	solve();

	return 0;
}