solve: 프로그래머스 문제 풀이 - 8일차

Author: OhChangEun

2025-08-20/오창은/[solved] 프로그래머스_다단계 칫솔 판매.java

@@ -0,0 +1,39 @@
+import java.util.*;
+
+class Solution {
+	Map<String, Integer> map = new HashMap<>();
+    Map<String, String> parentMap = new HashMap<>();
+    
+    public int[] solution(String[] enroll, String[] referral, String[] seller, int[] amount) {
+  		int size = enroll.length;	
+        int[] answer = new int[size];
+        
+        for (int i=0; i<size; i++) {
+            map.put(enroll[i], 0);
+            parentMap.put(enroll[i], referral[i]);
+        }
+        
+        for (int i=0; i<seller.length; i++) {
+            String man = seller[i];
+            int profit = amount[i] * 100;
+            dfs(man, profit);
+        }
+        
+        for (int i=0; i<size; i++) {
+            String man = enroll[i];
+            answer[i] = map.get(man);
+        }
+        // System.out.println(map);
+        return answer;
+    }
+    public void dfs(String man, int profit) {
+        if (man.equals("-") || profit == 0) {
+            return; 
+        }
+        int give = profit / 10;
+        int keep = profit - give;
+      	map.put(man, map.get(man) + keep); 
+        
+        dfs(parentMap.get(man), give);
+    }
+}

2025-08-20/오창은/[solved] 프로그래머스_다리를 지나는 트럭.java

@@ -0,0 +1,33 @@
+import java.util.*;
+
+class Solution {
+    public int solution(int bridge_length, int weight, int[] truck_weights) {
+        int answer = 0;
+       
+        Queue<Integer> bridge = new LinkedList<>();
+      	for (int i=0; i<bridge_length; i++) {
+            bridge.offer(0);
+        } 
+        
+        int time = 0;
+        int currWeight = 0;
+        int idx = 0;
+        while (!bridge.isEmpty()) {
+            time++;
+           
+            currWeight -= bridge.poll();
+            if (idx < truck_weights.length) {
+                if (currWeight + truck_weights[idx] <= weight) {
+                    bridge.offer(truck_weights[idx]);
+                    currWeight += truck_weights[idx];
+                    idx++;
+            	}
+                else {
+                    bridge.offer(0);
+                }
+            }
+        }
+        
+        return time;
+    }
+}

2025-08-20/오창은/[solved] 프로그래머스_소수찾기.java

@@ -0,0 +1,45 @@
+import java.util.*;
+
+class Solution {
+   	Set<Integer> set = new HashSet<>();	
+    
+    public boolean isPrime(int n) {
+        if (n < 2) return false; 
+        if (n == 2) return true; 
+        if (n % 2 == 0) return false; 
+        
+        for (int i=3; i<=Math.sqrt(n); i++) {
+            if (n % i == 0) return false;
+        }
+        return true;
+    } 
+    
+    public int solution(String numbers) {
+    	boolean[] visited = new boolean[numbers.length()];
+        dfs(numbers, "", visited);
+  
+        int answer = 0;
+        for (int num: set) {
+            if (isPrime(num)) {
+               	answer++; 
+            }
+        }
+       	// boolean isTrue = isPrime(2);
+        // System.out.println(isTrue);
+        return answer;
+    }
+    
+    public void dfs(String numbers, String curr, boolean[] visited) {
+       	if (!curr.equals("")) {
+          	set.add(Integer.parseInt(curr));
+        } 
+        
+        for (int i=0; i<numbers.length(); i++) {
+            if (!visited[i]) {
+                visited[i] = true;
+            	dfs(numbers, curr + numbers.charAt(i), visited);
+                visited[i] = false;
+            }
+        }
+    }
+}