Java实现洛谷 P1873 砍树（StreamTokenizer+IO+二分）-蒲公英云

Java实现洛谷 P1873 砍树（StreamTokenizer+IO+二分）

我就是我 2023-07-21 11:14 43阅读 0赞

P1873 砍树

在这里插入图片描述

输入输出样例
输入  
5 20
4 42 40 26 46
输出 
36

PS：
get新知识，以前只知道STringTokenizer并没有了解过StreamTokenizer，这次才知道
原来io输入的jdk提供了方法接收这个，大概感觉貌似差不多，好久没用io了，一边百度一边用
现学现卖哈哈

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.StreamTokenizer;
public class 砍树 { 
    public static void main(String[] args) throws IOException {     
        StreamTokenizer in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
        PrintWriter out = new PrintWriter(new OutputStreamWriter(System.out));
        in.nextToken();
        int n = (int)in.nval;
        in.nextToken();
        int m = (int)in.nval;
        int[] s = new int[n];
        int l = 0,r = 0;
        for(int i = 0;i < n;i++) { 
            in.nextToken();
            s[i] = (int)in.nval;
            r = Math.max(r, s[i]);
        }
        while(l <= r) { 
            int mid = (l + r) / 2;
            if(judge(mid,s,m)) { 
                l = mid + 1;
            }else { 
                r = mid - 1;
            }
        }
        out.print(l - 1);
        out.close();
    }
    public static boolean judge(int mid,int[] s,int m) { 
        int sum = 0;
        for(int i = 0;i < s.length;i++) { 
            if(s[i] > mid) { 
                sum += (s[i] - mid);
                if(sum >= m) { 
                    return true;
                }
            }
        }
        return false;
    }
}