완전 탐색 공부 위주로

Basic_Of_Algorithm/src/Today_22_05_26/backJoon_antenna.java

@@ -0,0 +1,55 @@
+package Today_22_05_26;
+
+import java.util.Scanner;
+
+import java.util.Arrays;
+
+public class backJoon_antenna {
+
+	public static void main(String[] args) {
+
+		Scanner scan = new Scanner(System.in);
+
+		int n = scan.nextInt();
+
+		int[]arr = new int[n];
+
+		for(int i=0;i<n;i++) arr[i] = scan.nextInt();
+
+		Arrays.sort(arr);
+
+		int answer = 0;
+
+
+		if(n%2==0) {
+			int one = 0;
+			int two = 0;
+
+			for(int i=0;i<arr.length;i++) {
+				one += Math.abs(arr[arr.length/2] - arr[i]);
+
+			}
+
+			System.out.println(arr.length/2);
+			for(int i=0;i<arr.length;i++) {
+				two += Math.abs(arr[(arr.length/2)-1] - arr[i]);
+			}
+
+			answer = Math.min(one, two);
+
+
+		}else {
+
+			for(int i=0;i<arr.length;i++) {
+
+				answer += Math.abs(arr[arr.length/2-1] - arr[i]);
+
+			}
+
+		}
+
+
+		System.out.println(answer);
+
+	}
+}

Basic_Of_Algorithm/src/Today_22_05_26/backJoon_color.java

@@ -0,0 +1,85 @@
+package Today_22_05_26;
+
+public class backJoon_color {
+
+	public static void main(String[] args) {
+
+		String [] color = {"RRRBB","GGBBB","BBBRR","BBRRR","RRRRR"};
+		char[][] map = new char[color.length][color[0].length()];
+
+		boolean[][] visited = new boolean[map.length][map[0].length];
+		boolean[][] visited2 = new boolean[map.length][map[0].length];
+
+		int normal = 0;
+		int special = 0;
+
+
+		for(int i=0;i<color.length;i++) {
+			for(int j=0;j<color[0].length();j++) {
+				map[i][j] = color[i].charAt(j);
+			}
+		}
+
+
+		for(int i=0;i<map.length;i++) {
+			for(int j=0;j<map[0].length;j++) {
+				if(!visited[i][j]) {
+					dfs(visited,map,i,j);
+					normal++;
+				}
+			}
+		}
+		System.out.println(normal);
+
+		for(int i=0;i<map.length;i++) {
+			for(int j=0;j<map[0].length;j++) {
+				if(map[i][j]=='R') map[i][j]='G';
+			}
+		}
+
+		for(int i=0;i<map.length;i++) {
+			for(int j=0;j<map[0].length;j++) {
+				if(!visited2[i][j]) {
+					dfs(visited2,map,i,j);
+					special++;
+				}
+			}
+		}
+
+
+
+		System.out.println(special);
+
+	}
+
+	static void dfs(boolean[][]visited, char[][]map,int i,int j) {
+
+		visited[i][j] = true;
+
+
+		int[][]move = {{0,1},{1,0},{0,-1},{-1,0}};
+
+
+		for(int d=0;d<4;d++) {
+
+			int newI = i + move[d][0];
+			int newJ = j + move[d][1];
+
+			if(newI<0||newJ<0||map.length-1<newI||map[0].length-1<newJ) continue;
+
+			if(map[i][j]==map[newI][newJ] && !visited[newI][newJ]) {
+				dfs(visited,map,newI,newJ);
+			}
+
+		}
+
+
+
+
+
+
+
+
+
+	}
+}

Basic_Of_Algorithm/src/Today_22_05_26/backJoon_combination.java

@@ -0,0 +1,47 @@
+package Today_22_05_26;
+
+import java.util.*;
+
+public class backJoon_combination {
+
+
+	public static void main(String[] args) {
+
+	Scanner scan = new Scanner(System.in);
+
+	int n = scan.nextInt();
+	int m = scan.nextInt();
+	int [] arr = new int[n];
+
+	for(int i=0;i<n;i++) arr[i] = i+1;
+
+
+
+	combi(arr,m,"");
+
+
+
+
+
+
+	}
+
+	static void combi(int[]arr,int count,String now) {
+
+
+		if(count==0) {
+			System.out.println(now);
+			return;
+		}
+
+
+
+		for(int i=0;i<arr.length;i++) {
+			String newOne = arr[i]+ " " + now;
+			combi(arr,count-1,newOne);
+		}
+
+
+
+	}
+}

Basic_Of_Algorithm/src/Today_22_05_26/programmers_bruteForce.java

@@ -0,0 +1,70 @@
+package Today_22_05_26;
+
+import java.util.*;
+
+public class programmers_bruteForce {
+
+	static int answer = 0;
+	static Set<Integer>set = new HashSet<>();
+
+
+	public static void main(String[] args) {
+
+
+		String numbers = "17";
+
+
+
+		boolean[]visited = new boolean[numbers.length()];
+
+		dfs(numbers,visited,"");
+
+		System.out.println(set.size());
+		System.out.println(set);
+
+	}
+
+	static void dfs(String numbers,boolean [] visited,String now) {
+
+		if(!now.isEmpty()) {
+
+
+			int temp = Integer.parseInt(now);
+			boolean flag = true;
+
+			if(temp==2) flag = true;
+			else if(temp==1 || temp==0) flag = false;
+
+
+			for(int i=2;i<=Math.sqrt(temp);i++) {
+
+				if(temp%i==0) {
+					flag = false;
+					break;
+				}
+
+			}
+
+			if(flag) set.add(temp);
+		}
+
+
+
+
+		for(int i = 0 ; i<numbers.length();i++) {
+
+			if(!visited[i]) {
+				visited[i] = true;
+				String newOne = now + numbers.charAt(i);
+				dfs(numbers,visited,newOne);
+				visited[i] = false;
+			}
+
+
+		}
+
+
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_26/rightBigNumber.java

@@ -0,0 +1,39 @@
+package Today_22_05_26;
+
+import java.util.Stack;
+
+public class rightBigNumber {
+
+	public static void main(String[] args) {
+
+		int []arr = {1,5,3,0,2};
+
+		Stack<Integer> temp = new Stack<>();
+		Stack<Integer> pra = new Stack<>();
+
+		//5 3 2 2 0
+
+		for(int i=arr.length-1;i>-1;i--) {
+
+			int num = arr[i];
+
+			while(!temp.isEmpty() && num>= temp.peek()) {
+				temp.pop();
+			}
+
+			if(temp.isEmpty()) {
+				pra.add(-1);
+			}else {
+				pra.add(temp.peek());
+			}
+
+			temp.add(num);
+
+
+
+
+		}
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_26/test.java

@@ -0,0 +1,35 @@
+package Today_22_05_26;
+
+import java.util.*;
+
+public class test {
+
+	public static void main(String[] args) {
+
+
+		int[]arr = {3,7,1,5};
+					//-1 5 -1 7 stack
+
+		Stack<Integer>temp = new Stack<>();
+		Stack<Integer>ans = new Stack<>();
+
+
+		for(int i=arr.length-1;i>-1;i--) {
+
+			int num = arr[i];
+
+
+			while(!temp.isEmpty()&&num>=temp.peek()) temp.pop();
+
+
+			if(temp.isEmpty()) ans.add(-1);
+			else ans.add(temp.peek());
+
+			temp.add(num);
+
+		}
+
+
+		System.out.println(ans);
+	}
+}

Basic_Of_Algorithm/src/Today_22_05_26/twoPointer.java

@@ -0,0 +1,48 @@
+package Today_22_05_26;
+
+import java.util.*;
+
+public class twoPointer {
+
+	public static void main(String[] args) {
+
+		int [] two = {1,1,2,2,3,3};
+					//1,1,2,2,3,5,7
+		int target = 4;
+		int answer = 0;
+		//답 = 2
+		int start = 0;
+		int end = two.length-1;
+		Arrays.sort(two);
+
+
+
+		while(start<=end) {
+
+
+			int sum = two[start] + two[end];
+
+			if(sum<target) start++;
+			else if(start==end) break;
+			else end--;
+
+
+			if(target==sum)answer++;
+
+
+
+		}
+
+
+		System.out.println(answer);
+
+
+
+
+
+
+
+
+	}
+
+}