feat : 프로그래머스 dp 문제

Author: cyeji

src/main/java/sgyj/programmers/yeji/cs/Solution42839.java

@@ -1,46 +1,19 @@
 package sgyj.programmers.yeji.cs;
 
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 public class Solution42839 {
-    private static boolean[] visited;
-    private static Set<Integer> answer = new HashSet<>();
 
+    private static Set<Integer> primeSet = new HashSet<>();
+    private static boolean[] visited;
+    private static Character[] cm;
+    private static int answer = 0;
     public static int solution(String numbers) {
-        String[] numberStr = numbers.split("");
-        int n = numberStr.length;
-        visited = new boolean[n];
-        for(int i=0; i<n; i++){
-            visited[i] = true;
-            checkPrime(numberStr,i,n,numberStr[i],0);
-        }
-        return answer.size();
-    }
 
-    public static void checkPrime(String[] numberStr, int i, int n,String target, int count){
-        if(i==n && count != n) i=0;
-        if(i==n || count == n) return;
-        if(!visited[i]){
-            target += numberStr[i];
-        }
-        if(isPrime(Integer.valueOf(target))){
-            answer.add(Integer.valueOf(target));
-        }
-        visited[i] = true;
-        checkPrime(numberStr,i+1,n,target,count+1);
-        visited[i] = false;
-    }
 
-    public static boolean isPrime(int target){
-        boolean isPrime = true;
-        if(target == 0 || target == 1) return false;
-        for(int p=2; p<target; p++){
-            if(target % p == 0) {
-                isPrime = false;
-            }
-        }
-        return isPrime;
+        return answer;
     }
 
     public static void main ( String[] args ) {

src/main/java/sgyj/programmers/yeji/dp/Solution42895.java

@@ -0,0 +1,52 @@
+package sgyj.programmers.yeji.dp;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+// N으로 표현
+public class Solution42895 {
+    public static int solution(int N, int number) {
+        List<Set<Integer>> countList = new ArrayList<>();
+
+        for(int i=0; i<9; i++)
+            countList.add(new HashSet<>());
+
+        countList.get(1).add(N); // N을 1개 쓴 값은 N 혼자이다.
+
+        for(int i=2; i<9; i++){
+            Set<Integer> countSet = countList.get(i);
+
+            for(int j=1; j<=i; j++){
+                Set<Integer> preSet = countList.get(j);
+                Set<Integer> postSet = countList.get(i - j);
+
+                for(int preNum : preSet){
+                    for(int postNum : postSet){
+                        countSet.add(preNum + postNum);
+                        countSet.add(preNum - postNum);
+                        countSet.add(preNum * postNum);
+
+                        if(preNum != 0 && postNum != 0)
+                            countSet.add(preNum / postNum);
+                    }
+                }
+            }
+
+            countSet.add(Integer.parseInt(String.valueOf(N).repeat(i)));
+        }
+
+        for(Set<Integer> sub : countList){
+            if(sub.contains(number))
+                return countList.indexOf(sub);
+        }
+
+        return -1;
+    }
+    public static void main ( String[] args ) {
+        int N = 2;
+        int number = 11;
+        System.out.println( solution(N,number) );
+    }
+}

src/main/java/sgyj/programmers/yeji/dp/Solution42898.java

@@ -0,0 +1,46 @@
+package sgyj.programmers.yeji.dp;
+
+public class Solution42898 {
+    private static int[][] distance;
+    private static int minDistance = Integer.MAX_VALUE;
+    private static int answer = 0;
+    public static int solution(int m, int n, int[][] puddles) {
+        distance = new int[n+1][m+1];
+        // 방문할수 없는 곳
+        for(int[] puddle : puddles){
+            distance[puddle[0]][puddle[1]] = -1;
+        }
+
+        findDistance(1,1,n,m,0);
+
+        return answer;
+    }
+
+    public static void findDistance(int x, int y, int n, int m,int i){
+        if((x==m && y == n-1) || (y==n && x==m-1)){
+            distance[x][y] = 0;
+            if(minDistance == i){
+                answer++;
+            }
+            if(minDistance>i){
+                minDistance = i;
+                answer = 1;
+            }
+            return;
+        }
+        if(x<n && y<m && distance[x][y] != -1){
+            distance[x][y] = i;
+            findDistance( x+1,y,n,m,i+1 );
+            findDistance( x,y+1,n,m,i+1 );
+        }
+
+    }
+
+    public static void main ( String[] args ) {
+        int m = 4;
+        int n = 3;
+        int[][] puddles = {{2,2}};
+
+        System.out.println(solution(m,n,puddles));
+    }
+}

src/main/java/sgyj/programmers/yeji/dp/Solution43105.java

@@ -0,0 +1,39 @@
+package sgyj.programmers.yeji.dp;
+
+public class Solution43105 {
+
+    public static int solution(int[][] triangle) {
+        int answer = 0;
+        int n = triangle.length;
+        int[][] visited = new int[n][triangle[n-1].length];
+        visited[0][0] = triangle[0][0];
+        for(int i=1; i<n; i++){
+            for(int j=0; j<=i; j++){
+               if(j==0){
+                   visited[i][j] = visited[i-1][j] + triangle[i][j];
+               }else if(j == i){
+                   visited[i][j] = visited[i-1][j-1] + triangle[i][j];
+               }else{
+                   int compare = triangle[i][j] + visited[i-1][j-1];
+                   int compare2 = triangle[i][j] + visited[i-1][j];
+                   int max = Math.max( compare2,compare );
+                   visited[i][j] = max;
+               }
+            }
+        }
+
+        for(int v : visited[n-1]){
+            answer = Math.max( answer,v );
+        }
+
+        return answer;
+    }
+
+    public static void main ( String[] args ) {
+        int[][] triangle = {
+            {7},{3,8},{8,1,0},{2,7,4,4},{4,5,2,6,5}
+        };
+
+        System.out.println(solution(triangle));
+    }
+}