[string] 문장 속 단어(indexOf(), substring())

import java.util.*;
class Main {	
	public String solution(String str){
		String answer="";
		int m=Integer.MIN_VALUE;
		String[] s = str.split(" ");
		for(String x : s){
			int len=x.length();
			if(len>m){
				m=len;
				answer=x;
			}
		}
		return answer;
	}

	public static void main(String[] args){
		Main T = new Main();
		Scanner kb = new Scanner(System.in);
		String str=kb.nextLine();
		System.out.print(T.solution(str));
	}
}

 

import java.util.*;
class Main {	
	public String solution(String str){
		String answer="";
		int m=Integer.MIN_VALUE, pos;
		while((pos=str.indexOf(' '))!=-1){
			String tmp=str.substring(0, pos);
			int len=tmp.length();
			if(len>m){
				m=len;
				answer=tmp;
			}
			str=str.substring(pos+1);
		}
		if(str.length()>m) answer=str;
		return answer;
	}

	public static void main(String[] args){
		Main T = new Main();
		Scanner kb = new Scanner(System.in);
		String str=kb.nextLine();
		System.out.print(T.solution(str));
	}
}

solution함수에서, answer에 담길 것은 가장 긴 단어
최댓값으로 항상 갱신해야하니 작은 값으로 초기화시키고 시작

str.split: 띄어쓰기로 구분해 분리하고 string배열에 저장