백준 그리디 알고리즘 위주로 공부!

Basic_Of_Algorithm/src/Today_22_05_20/bfs.java

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+package Today_22_05_20;
+
+import java.util.Queue;
+import java.util.LinkedList;
+
+public class bfs {
+
+	public static void main(String[] args) {
+
+		int[][] maps = {{1,0,1,1,1},{1,0,1,0,1},{1,0,1,1,1},{1,1,1,0,1},{0,0,0,0,1}};
+		int answer = 0;
+
+		Queue<int[]> q = new LinkedList<>();
+
+		int[][]temp = new int[maps.length][maps[0].length];
+
+		temp[0][0] = 1;
+
+		q.add(new int[] {0,0});
+
+		int[][]move = {{0,1},{1,0},{0,-1},{-1,0}};
+
+		while(!q.isEmpty()) {
+
+			int [] cur = q.poll();
+
+			int ni = cur[0];
+			int nj = cur[1];
+
+			for(int d=0;d<4;d++) {
+
+				int newI = ni + move[d][0];
+				int newJ = nj + move[d][1];
+
+				if(newI<0||newJ<0||maps.length-1<newI||maps[0].length-1<newJ) continue;
+
+				if(maps[newI][newJ]==1 && temp[newI][newJ]==0) {
+					temp[newI][newJ] = temp[ni][nj]+1;
+					q.add(new int[] {newI,newJ});
+				}
+
+			}
+
+
+		}
+
+		answer = temp[maps.length-1][maps[0].length-1];
+
+		System.out.println(answer);
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/dungeons.java

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+package Today_22_05_20;
+
+public class dungeons {
+
+	static int answer = 0;
+
+	public static void main(String[] args) {
+
+	int k = 80;
+	int[][]dungeons = {{80,20},{50,40},{30,10}};
+
+	boolean[]visited = new boolean[dungeons.length];
+
+	dfs(dungeons,visited,k,0);
+
+	System.out.println(answer);
+	}
+	static void dfs(int[][]dungeons,boolean[]visited,int k,int count) {
+
+		for(int i=0;i<dungeons.length;i++) {
+			if(!visited[i]&&dungeons[i][0]<=k) {
+				visited[i] = true;
+				int newK = k - dungeons[i][1];
+				dfs(dungeons,visited,newK,count+1);
+				visited[i] = false;
+			}
+
+		}
+
+
+		answer = Math.max(answer, count);
+
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greddy_changeMoney.java

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+package Today_22_05_20;
+
+import java.util.Scanner;
+
+public class greddy_changeMoney {
+
+	public static void main(String[] args) {
+
+		Scanner scan = new Scanner(System.in);
+
+		int cash = scan.nextInt();
+
+		//500 100 50 10 5 1
+
+		int[]arr = {500,100,50,10,5,1};
+
+		cash = 1000-cash;
+
+		int answer = 0;
+
+		for(int i=0;i<arr.length;i++) {
+
+			if(cash>=arr[i]) {
+
+				answer += cash/arr[i];
+				cash = cash%arr[i];
+			}
+			if(cash==0)break;
+		}
+
+
+		System.out.println(answer);
+
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greedy_atm.java

@@ -0,0 +1,33 @@
+package Today_22_05_20;
+
+import java.util.Scanner;
+import java.util.Arrays;
+
+public class greedy_atm {
+
+	public static void main(String[] args) {
+
+	Scanner scan = new Scanner(System.in);
+
+	int answer = 0;
+
+	int n = scan.nextInt();
+
+	int[]man = new int[n];
+
+	for(int i=0;i<n;i++) man[i] = scan.nextInt();
+
+	Arrays.sort(man);
+	int temp = 0;
+	for(int i=0;i<man.length;i++) {
+		temp += man[i];
+		answer += temp;
+	}
+
+	System.out.println(answer);
+
+
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greedy_bracket.java

@@ -0,0 +1,39 @@
+package Today_22_05_20;
+
+import java.util.Scanner;
+
+public class greedy_bracket {
+
+	public static void main(String[] args) {
+
+		Scanner scan = new Scanner(System.in);
+
+		String temp = scan.next();
+
+		String[]str = temp.split("\\-");
+
+		int answer = 0;
+
+		for(int i=0;i<str.length;i++) {
+
+			String[]subStr = str[i].split("\\+");
+
+			int calc = 0;
+			for(String item : subStr) {
+				calc += Integer.parseInt(item);
+			}
+
+			if(i==0) {
+				answer += calc;
+
+			}else {
+				answer -= calc;
+			}
+		}
+
+
+		System.out.println(answer);
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greedy_coin.java

@@ -0,0 +1,43 @@
+package Today_22_05_20;
+
+import java.util.Scanner;
+import java.util.Arrays;
+import java.util.Collections;
+public class greedy_coin {
+
+	public static void main(String[] args) {
+
+		Scanner scan = new Scanner(System.in);
+
+
+		int n = scan.nextInt();
+		int k = scan.nextInt();
+
+		int answer = 0;
+
+		Integer[]arr = new Integer[n];
+
+
+		for(int i=0;i<n;i++) arr[i] = scan.nextInt();
+
+		Arrays.sort(arr, Collections.reverseOrder());
+
+		for(int i=0;i<arr.length;i++) {
+
+			int coin = arr[i];
+
+
+			while(k>=coin) {
+				System.out.println(coin);
+				answer++;
+				k -= coin;
+			}
+
+
+		}
+
+		System.out.println(answer);
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greedy_coin2.java

@@ -0,0 +1,35 @@
+package Today_22_05_20;
+
+import java.util.Scanner;
+import java.util.Arrays;
+import java.util.Collections;
+public class greedy_coin2 {
+
+	public static void main(String[] args) {
+
+		Scanner scan = new Scanner(System.in);
+
+
+		int n = scan.nextInt();
+		int k = scan.nextInt();
+
+		int answer = 0;
+
+		Integer[]arr = new Integer[n];
+
+
+		for(int i=0;i<n;i++) arr[i] = scan.nextInt();
+
+		for(int i=arr.length-1;i>-1;i--) {
+
+			if(arr[i]<=k) {
+				answer += k/arr[i];
+				k = k%arr[i];
+			}
+
+		}
+
+		System.out.println(answer);
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greedy_sugar.java

@@ -0,0 +1,40 @@
+package Today_22_05_20;
+
+import java.io.InputStreamReader;
+import java.io.BufferedReader;
+public class greedy_sugar {
+
+	public static void main(String[] args) throws Exception {
+
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+		int n = Integer.parseInt(br.readLine());
+
+		//3 //5
+		int answer = 0;
+
+		//5의 배수도 3의 배수도 아닌 경우에도 나눠 떨어지는 애들이 있음!
+
+
+		while(true) {
+
+			if(n%5==0) {
+				answer += n/5;
+				break;
+			}else {
+				answer ++;
+				n -= 3;
+			}
+
+			if(n<0) {
+				answer = -1;
+				break;
+			}
+
+		}
+
+		System.out.println(answer);
+
+	}
+
+}

Basic_Of_Algorithm/src/Today_22_05_20/greedy_wordsMath.java

@@ -0,0 +1,42 @@
+package Today_22_05_20;
+
+import java.util.Scanner;
+
+public class greedy_wordsMath {
+
+	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<arr.length;i++) arr[i] = scan.nextInt();
+
+		int answer = 0;
+
+		int nPoint = arr[arr.length-1];
+
+
+
+		for(int i=arr.length-2;i>-1;i--) {
+
+			int pre = arr[i];
+			while(nPoint<=pre) {
+
+				answer++;
+				pre--;
+
+			}
+
+			nPoint = pre;
+
+
+		}
+
+
+		System.out.println(answer);
+
+	}
+}