18-SeongHoonC

SeongHoonC/README.md

@@ -18,4 +18,6 @@
 | 14차시 | 2024.03.06 | dfs | <a href="https://school.programmers.co.kr/learn/courses/30/lessons/64064"></a> |https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/50 |
 | 15차시 | 2024.03.09 | 분할정복 | <a href="https://www.acmicpc.net/problem/1629"></a> |https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/55 |
 | 16차시 | 2024.03.14 | 누적합 | <a href="https://www.acmicpc.net/problem/11659"></a> |https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/60 |
+| 17차시 | 2024.03.17 | 특정한 최단 경로 | <a href="https://www.acmicpc.net/problem/1504"></a> |https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/62 |
+| 18차시 | 2024.03.28 | 구현 | <a href="https://www.acmicpc.net/problem/16234"></a> |https://github.com/AlgoLeadMe/AlgoLeadMe-6/pull/70 |
 ---

SeongHoonC/구현/인구이동.kt

@@ -0,0 +1,90 @@
+import java.io.BufferedReader
+import java.io.InputStreamReader
+import java.util.*
+import kotlin.collections.ArrayDeque
+import kotlin.math.*
+
+val dx = listOf(1, -1, 0, 0)
+val dy = listOf(0, 0, 1, -1)
+fun main() {
+    val br = BufferedReader(InputStreamReader(System.`in`))
+    val (n, l, r) = br.readLine().split(" ").map { it.toInt() }
+    val grounds = Array(n) { Array(n) { 0 } }
+
+    for (i in 0 until n) {
+        val line = br.readLine().split(" ").map { it.toInt() }
+        for (j in 0 until n) {
+            grounds[i][j] = line[j]
+        }
+    }
+    var count = 0
+    // 인구가 더이상 이동할 수 없을 때까지 반복
+    while (moving(grounds, n, l, r)) {
+        count++
+    }
+    println(count)
+}
+
+// L 명 이상 R 명 이하면 인구 이동하기
+private fun moving(grounds: Array<Array<Int>>, n: Int, l: Int, r: Int): Boolean {
+    val visited = Array(n) { Array(n) { false } }
+
+    val unities = mutableListOf<List<Pair<Int, Int>>>()
+    for (i in 0 until n) {
+        for (j in 0 until n) {
+            val unity = bfs(grounds, n, visited, i to j, l, r) ?: continue
+            unities.add(unity)
+        }
+    }
+    if (unities.isEmpty()) return false
+
+    unities.forEach { goAverage(grounds, it) }
+
+    return true
+}
+
+// 연합들을 평균값으로 변경
+private fun goAverage(grounds: Array<Array<Int>>, unity: List<Pair<Int, Int>>) {
+    val average = unity.sumOf { grounds[it.first][it.second] } / unity.size
+    unity.forEach {
+        grounds[it.first][it.second] = average
+    }
+}
+
+// bfs 로 연합 다 찾기
+private fun bfs(
+    grounds: Array<Array<Int>>,
+    n: Int,
+    visited: Array<Array<Boolean>>,
+    start: Pair<Int, Int>,
+    l: Int,
+    r: Int,
+): List<Pair<Int, Int>>? {
+    if (visited[start.first][start.second]) return null
+    val deque = ArrayDeque<Pair<Int, Int>>()
+    val unity = mutableListOf<Pair<Int, Int>>()
+    deque.add(start)
+    unity.add(start)
+    visited[start.first][start.second] = true
+    while (deque.isNotEmpty()) {
+        val now = deque.removeFirst()
+        for (i in 0..3) {
+            val nextX = now.first + dx[i]
+            val nextY = now.second + dy[i]
+            if (nextX < 0 || nextX >= n || nextY < 0 || nextY >= n) {
+                continue
+            }
+            if (visited[nextX][nextY]) {
+                continue
+            }
+            if (abs(grounds[nextX][nextY] - grounds[now.first][now.second]) !in l..r) {
+                continue
+            }
+            visited[nextX][nextY] = true
+            deque.add(nextX to nextY)
+            unity.add(nextX to nextY)
+        }
+    }
+    if (unity.size == 1) return null
+    return unity
+}