5. Array Manipulation.java

import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner sc=new Scanner(System.in);
                
                long N=sc.nextLong();
                long M=sc.nextLong();
                
                long A[]=new long[(int)N+1];
                for(int i=1;i<=N;i++) A[i]=0;
                
                long max=0,sum=0;;
                
                long a;
                long b;
                long k;
                
                for(int i=1;i<=M;i++)
                    {
                        a=sc.nextLong();
                        b=sc.nextLong();
                        k=sc.nextLong();
                        A[(int)a]+=k;
                        if(b<N)A[(int)b+1]-=k;
                    }
                
                
                
                
                
                for(int i=1;i<=N;i++) 
                    {
                        sum+=A[i];
                        if(sum>max) max=sum;
                    }
                System.out.println(max);
    }
}