마법사 상어와 파이어스톰 C++

https://www.acmicpc.net/problem/20058

20058번: 마법사 상어와 파이어스톰

#include <iostream>
#include <cmath>
#include <cstring>

const int MAX = 65;
int a[MAX][MAX];
int visited[MAX][MAX];
int n, q, l;
int temp_num = 0;
struct Ice { int x, y; };
Ice ic[4] = { { -1,0 },{ 1,0 },{ 0,1 },{ 0,-1 } };
int temp[MAX][MAX];
int pow_n;

using namespace std;

void DivideMap() {
	int pow_l = pow(2, l);

	int count = pow_n / pow_l;
	int count2 = count;
	int index_i = 1;

	while (count > 0) {
		int range_i = index_i + pow_l;
		int index_j = 1;
		while (count2 > 0)
		{
			int ii = index_i;
			int range_j = index_j + pow_l;
			int jj = range_j - 1;
			for (; index_i < range_i; index_i++) {
				for (; index_j < range_j; index_j++) {
					temp[ii][jj] = a[index_i][index_j];
					ii += 1;
				}
				jj -= 1;
				ii -= pow_l;
				index_j -= pow_l;
			}
			index_j += pow_l;
			count2--;
			index_i -= pow_l;
		}
		index_i += pow_l;
		count--;
		count2 = pow_n / pow_l;
	}


	for (int i = 1; i <= pow_n; i++) {
		for (int j = 1; j <= pow_n; j++) {
			a[i][j] = temp[i][j];
		}
	}
}

void ReduceIce() {

	int movei, movej;

	for (int i = 1; i <= pow_n; i++) {
		for (int j = 1; j <= pow_n; j++) {
			int count = 0;
			if (temp[i][j] > 0) {
				for (int k = 0; k < 4; k++) {
					movei = i + ic[k].x;
					movej = j + ic[k].y;

					if (movei > 0 && movej > 0 && movei <= pow_n && movej <= pow_n) {
						if (temp[movei][movej] > 0)
							count++;
					}
				}
				if (count < 3)
					a[i][j] -= 1;
			}
		}
	}
}

void dfs(int i, int j) {
	visited[i][j] = 1;

	for (int k = 0; k < 4; k++) {
		int movei = i + ic[k].x;
		int movej = j + ic[k].y;

		if (movei > 0 && movej > 0 && movei <= pow_n && movej <= pow_n && visited[movei][movej] != 1 && a[movei][movej] >0) {
			temp_num++;
			dfs(movei, movej);
		}
	}
}

int Find_Ice() {
	memset(visited, -1, sizeof(visited));
	int answer = 0;
	int count = 0;

	for (int i = 1; i <= pow_n; i++) {
		for (int j = 1; j <= pow_n; j++) {
			count += a[i][j];
			if (a[i][j] > 0 && visited[i][j] != 1) {
				temp_num = 1;
				dfs(i, j);
				if (temp_num > answer)
					answer = temp_num;
			}
		}
	}
	cout << count << endl;
	return answer;
}

int main(void) {
	cin >> n >> q;
	pow_n = pow(2, n);

	for (int i = 1; i <= pow_n; i++) {
		for (int j = 1; j <= pow_n; j++) {
			cin >> a[i][j];
		}
	}

	for (int i = 0; i < q; i++) {
		cin >> l;

		DivideMap();
		ReduceIce();
	}
	cout << Find_Ice() << endl;
}