hihocoder55

http://hihocoder.com/contest/offers55/problems
题目1 : 算式最大值
有负号，再判断有没有括号

package l551;

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n=sc.nextInt(),p=sc.nextInt(),q=sc.nextInt(),k=sc.nextInt();
        int[]a=new int[n];
        for(int i=0;i

题目2 : 朋友字符串
直接暴力AC

package l552;

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n=sc.nextInt();
        String[]ss=new String[n];
        Sets=new HashSet();
        for(int i=0;i

题目3 : 区间覆盖问题
区间合并再二分，第一次run time error，那多半是数组越界，找到强行用a[0]这样的地方，然后就想到ArrayList L可能是空的

package l553;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
import java.util.Stack;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n=sc.nextInt(),q=sc.nextInt();
        int[][]a=new int[n][2];
        for(int i=0;i(){
            public int compare(int[] o1, int[] o2) {
                return o1[0]-o2[0];
            }
        });
        Stackst=new Stack();
        st.push(a[0]);
        for(int i=1;it[1]) {
                st.push(a[i]);
            } else {
                st.pop();
                st.push(new int[]{t[0],Math.max(t[1], a[i][1])});
            }
        }
        Stackst2=new Stack();
        while(!st.isEmpty()) st2.push(st.pop());
        Listl=new ArrayList();
        while(!st2.isEmpty()) l.add(st2.pop());
        Listt=new ArrayList();
        if(l.get(0)[0]>1) t.add(new int[]{1,l.get(0)[0]-1});
        for(int i=1;i1)
                t.add(new int[]{l.get(i-1)[1]+1, l.get(i)[0]-1});
        int[]b=new int[t.size()];
        b[0]=t.get(0)[1]-t.get(0)[0]+1;
        for(int i=1;i0) {
            int k=sc.nextInt();
            int idx=Arrays.binarySearch(b, k);
            if(idx>=0) System.out.println(t.get(idx)[1]);
            else {
                idx = -(idx+1);
                if(idx==0) System.out.println(t.get(0)[0]+k-1);
                else if(idx==b.length) System.out.println(l.get(l.size()-1)[1]+k-b[idx-1]);
                else System.out.println(t.get(idx)[0]+k-b[idx-1]-1);
            }
        }
    }
}

package l553;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
import java.util.Stack;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n=sc.nextInt(),q=sc.nextInt();
        int[][]a=new int[n][2];
        for(int i=0;i(){
            public int compare(int[] o1, int[] o2) {
                return o1[0]-o2[0];
            }
        });
        Stackst=new Stack();
        st.push(a[0]);
        for(int i=1;it[1]) {
                st.push(a[i]);
            } else {
                st.pop();
                st.push(new int[]{t[0],Math.max(t[1], a[i][1])});
            }
        }
        Stackst2=new Stack();
        while(!st.isEmpty()) st2.push(st.pop());
        Listl=new ArrayList();
        while(!st2.isEmpty()) l.add(st2.pop());
        Listt=new ArrayList();
        if(l.get(0)[0]>1) t.add(new int[]{1,l.get(0)[0]-1});
        for(int i=1;i1)
                t.add(new int[]{l.get(i-1)[1]+1, l.get(i)[0]-1});
        
        if(t.size()==0) {
            for(int k : qs) System.out.println(l.get(l.size()-1)[1]+k);
            return;
        }
        
        int[]b=new int[t.size()];
        b[0]=t.get(0)[1]-t.get(0)[0]+1;
        for(int i=1;i=0) System.out.println(t.get(idx)[1]);
            else {
                idx = -(idx+1);
                if(idx==0) System.out.println(t.get(0)[0]+k-1);
                else if(idx==b.length) System.out.println(l.get(l.size()-1)[1]+k-b[idx-1]);
                else System.out.println(t.get(idx)[0]+k-b[idx-1]-1);
            }
        }
    }
}