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13706번: 제곱근

• 아영

  • 코드

  **package Baekjoon.java.silver;
  
  import java.io.BufferedReader;
  import java.io.InputStreamReader;
  import java.math.BigInteger;
  
  public class boj13706 {
      public static void main(String[] args) throws Exception{
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          BigInteger N = new BigInteger(br.readLine());
          BigInteger left = BigInteger.ONE;
          BigInteger right = N;
          BigInteger n = BigInteger.ONE;
          while(n.compareTo(N)!=0){
              n = left.add(right).divide(BigInteger.TWO);
              if(n.pow(2).compareTo(N)==0){
                  break;
              }else if(n.pow(2).compareTo(N) == 1){
                  right = n;
              }else if(n.pow(2).compareTo(N) == -1){
                  left = n;
              }
          }
  
          System.out.println(n);
      }
  }**
  

  • 시간,메모리

  

• 은영

  • 코드

  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.math.BigInteger;
  	
  public class baekjoon13706 {
  	public static void main(String[] args) throws IOException {
  		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  		BigInteger N = new BigInteger(br.readLine());
  		
  		BigInteger one = new BigInteger("1");
  		BigInteger two = N;
  		
  		BigInteger ans;
  		
  	     while (true) {
  	    	 ans = one.add(two);
  	    	 ans = ans.divide(new BigInteger("2"));
  	 
  	            int result = (ans.multiply(ans)).compareTo(N);
  	            if (result == 0) break;
  	            else if (result == 1) two = ans.subtract(new BigInteger("1"));
  	            else one = ans.add(new BigInteger("1"));
  	        }
  		System.out.println(ans);
  		
  	}
  }
  

  • 시간,메모리

  

• 건

  • 코드

  package day_0411;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.math.BigInteger;
  
  public class BOJ13706 {
  	
  	static BigInteger n;
  	
  	public static void main(String[] args) throws IOException{
  		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  		n = new BigInteger(br.readLine());
  		
  		BigInteger answer = bSearch();
  		
  		System.out.println(answer);
  	}
  	
  	static BigInteger bSearch() {
  		BigInteger start = BigInteger.ONE;
  		BigInteger end = n;
  		BigInteger mid;
  		
  		while(start.compareTo(end) < 0) {
  			mid = start.add(end).divide(BigInteger.valueOf(2));
  			if (mid.pow(2).compareTo(n) == 0) {
  				return mid;
  			} else if (mid.pow(2).compareTo(n) > 0){
  				end = mid.add(BigInteger.ONE);
  			} else {
  				start = mid.add(BigInteger.valueOf(-1));
  			}
  		}
  		return BigInteger.valueOf(-1);
  	}
  }
  

  • 시간,메모리

  

• 용문

  • 코드
  • 시간,메모리