백준 9단계 (기본 수학2)

1978번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException {
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st;
        
        int cnt = 0;
        int N = Integer.parseInt(br.readLine());
        st = new StringTokenizer(br.readLine()," ");
        
        while(st.hasMoreTokens()) {
            
            boolean flag = true;
            
            int temp = Integer.parseInt(st.nextToken());
            
            if(temp == 1)
                continue;
            
            for(int i = 2; i <= temp / 2; i++) {
                if(temp % i == 0) {
                    flag = false;
                    break;
                }
            }
            
            if(flag)
                cnt++;
        }
        
        System.out.println(cnt);
    }
    
}

 

 

2581번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;
 
public class Main {
    public static boolean check[];
    public static void main(String[] args) throws IOException {
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        StringTokenizer st;
        
        int sum = 0;
        int start = Integer.parseInt(br.readLine());
        int end = Integer.parseInt(br.readLine());
        
        check = new boolean[end + 1];
        
        check_prime();
        
        for(int i = start; i <= end; i++) {
            if(!check[i]) {
                if(sum == 0) {
                    sb.append(i);
                }
                sum += i;
            }
        }
        
        if(sum == 0) {
            sb.append(-1);
        }
        else {
            sb.insert(0, sum + "\n");
        }
        
        System.out.println(sb);
        
    }
    
    public static void check_prime() {
        
        check[1] = true;
        
        for(int i= 2; i < check.length; i++) {
            for(int j = 2; i*j < check.length; j++) {
                check[i*j] = true;
            }
        }
        
    }
    
}

 

 

11653번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
 
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        StringBuilder sb = new StringBuilder();
        
        int N = Integer.parseInt(br.readLine());
        int i = 2;
        while(N >= i) {
            if(N % i == 0) {
                sb.append(i).append("\n");
                N /= i;
            }
            else
                i++;
        }
        System.out.println(sb);
        
    }
    
}

 

 

1929번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Main {
    public static boolean check[];
    public static void main(String[] args) throws NullPointerException, IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        StringBuilder sb = new StringBuilder();
        StringTokenizer st;
        
        st = new StringTokenizer(br.readLine()," ");
        int M = Integer.parseInt(st.nextToken());
        int N = Integer.parseInt(st.nextToken());
        
        check = new boolean[N+1];
        
        check_prime();
        
        for(int i = M; i <= N; i++) {
            if(!check[i])
                sb.append(i + "\n");
        }
        
        System.out.println(sb);
    }
    
    public static void check_prime() {
            
        check[1] = true;
        
        for(int i= 2; i < check.length; i++) {
            for(int j = 2; i*j < check.length; j++) {
                check[i*j] = true;
            }
        }
        
    }
 
}

 

 

4948번

import java.io.*;
import java.util.*;
 
public class Main {
    public static boolean check[] = new boolean[246913];
    public static void main(String[] args) throws IOException {
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        
        check_prime();
        
        while(true) {
            int cnt = 0;
            int N = Integer.parseInt(br.readLine());
            
            if(N == 0)
                break;
            
            for(int i = N + 1; i <= 2 * N; i++) {
                if(!check[i])
                    cnt++;
            }
            
            sb.append(cnt + "\n");
        }
        
        System.out.println(sb);
    }
    
    public static void check_prime() {
        
        check[1] = true;
        
        for(int i= 2; i < check.length; i++) {
            for(int j = 2; i*j < check.length; j++) {
                check[i*j] = true;
            }
        }       
    }
    
}

 

 

9020번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
 
public class Main {
    public static boolean[] check = new boolean[10001];
    public static void main(String[] args) throws NumberFormatException, IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        
        check_prime();
        
        int N = Integer.parseInt(br.readLine());
        
        for(int i = 0; i < N; i++) {
            int num = Integer.parseInt(br.readLine());
            int front = num / 2;
            int back = num / 2;
            
            while(true) {
                if(!check[front] && !check[back]) {
                    sb.append(front + " " + back).append("\n");
                    break;
                }
                front--;
                back++;
            }
        }
        
        System.out.println(sb);
        
    }
    
    public static void check_prime() {
        
        check[1] = true;
        
        for(int i= 2; i < check.length; i++) {
            for(int j = 2; i*j < check.length; j++) {
                check[i*j] = true;
            }
        }
        
    }
}

 

 

1085번

import java.io.*;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException{
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        
        StringTokenizer st;
        
        st = new StringTokenizer(br.readLine()," ");
        
        int x = Integer.parseInt(st.nextToken());
        int y = Integer.parseInt(st.nextToken());
        int w = Integer.parseInt(st.nextToken());
        int h = Integer.parseInt(st.nextToken());
        
        int min_x = (x-0) > (w-x)? (w-x) : (x-0);
        int min_y = (y-0) > (h-y)? (h-y) : (y-0);
        
        System.out.println(min_x > min_y ? min_y : min_x);
        
    }
}

 

 

3009번

import java.util.*;
import java.io.*;
 
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        StringBuilder sb = new StringBuilder();
        StringTokenizer st;
        
        int arr[] = new int[8];
        
        st = new StringTokenizer(br.readLine()," ");
        arr[0] = Integer.parseInt(st.nextToken());
        arr[1] = Integer.parseInt(st.nextToken());
        
        st = new StringTokenizer(br.readLine()," ");
        arr[2] = Integer.parseInt(st.nextToken());
        arr[3] = Integer.parseInt(st.nextToken());
        
        st = new StringTokenizer(br.readLine()," ");
        arr[4] = Integer.parseInt(st.nextToken());
        arr[5] = Integer.parseInt(st.nextToken());
        
        if(arr[0] == arr[2])
            sb.append(arr[4] + " ");
        else if(arr[0] == arr[4])
            sb.append(arr[2] + " ");
        else
            sb.append(arr[0] + " ");
        
        if(arr[1] == arr[3])
            sb.append(arr[5]);
        else if(arr[1] == arr[5])
            sb.append(arr[3]);
        else
            sb.append(arr[1]);
        
        System.out.println(sb);    
    }
}

 

 

4153번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException {
        StringBuilder sb = new StringBuilder();
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        
        StringTokenizer st;
        
        int x, y, z;
        
        while(true) {
            st = new StringTokenizer(br.readLine()," ");
            
            x =  Integer.parseInt(st.nextToken());
            y =  Integer.parseInt(st.nextToken());
            z =  Integer.parseInt(st.nextToken());
            
            if(x == 0 && y == 0 && z == 0)
                break;
            
            if((x*x) == (y*y)+(z*z)) {
                sb.append("right" + "\n");
            }
            else if((y*y) == (x*x)+(z*z)) {
                sb.append("right" + "\n");
            }
            else if((z*z) == (y*y)+(x*x)) {
                sb.append("right" + "\n");
            }
            else {
                sb.append("wrong" + "\n");
            }
        }
        
        System.out.println(sb);
            
    }
}

 

 

3053번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException {
    StringBuilder sb = new StringBuilder();
    
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
    
    StringTokenizer st;
    
    double pie = 3.141592653589;
    
    double R = Integer.parseInt(br.readLine());
    
    System.out.printf("%06f",pie * R * R);
    System.out.println();
    System.out.printf("%06f",2 * R * R);
        
    }
}

 

 

1002번

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Main {
    public static void main(String[] args) throws IOException {    
        
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); 
        StringTokenizer st;
        StringBuilder sb = new StringBuilder();
        int T = Integer.parseInt(br.readLine());
        
        for(int i = 0; i < T; i++) {
            
            st = new StringTokenizer(br.readLine()," ");
            
            int x1 = Integer.parseInt(st.nextToken());
            int y1 = Integer.parseInt(st.nextToken());
            int r1 = Integer.parseInt(st.nextToken());
            
            int x2 = Integer.parseInt(st.nextToken());
            int y2 = Integer.parseInt(st.nextToken());
            int r2 = Integer.parseInt(st.nextToken());
            
            int A = (int) (Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
            int B = (int) Math.pow(r1 + r2, 2);
            
            if(x1 == x2 && y1 == y2 && r1 == r2)
                sb.append(-1 + "\n");
            
            else if(A > B)
                sb.append(0 + "\n");
            
            else if(A == B)
                sb.append(1 + "\n");
            
            else if(A < (int) Math.pow(r2 - r1, 2))
                sb.append(0 + "\n");
            
            else if(A == (int) Math.pow(r2 - r1, 2))
                sb.append(1 + "\n");
            
            else
                sb.append(2 + "\n");
        }
        
        System.out.println(sb);
    }
 
}