Array Manipulation Hackerrank

Array Manipulation

Starting with a 1-indexed array of zeros and a list of operations, for each operation add a value to each the array element between two given indices, inclusive. Once all operations have been performed, return the maximum value in the array.

Example

Queries are interpreted as follows:

Add the values of between the indices and inclusive:

index->	 1 2 3  4  5 6 7 8 9 10
	[0,0,0, 0, 0,0,0,0,0, 0]
	[3,3,3, 3, 3,0,0,0,0, 0]
	[3,3,3,10,10,7,7,7,0, 0]
	[3,3,3,10,10,8,8,8,1, 0]

The largest value is after all operations are performed.

Function Description

Complete the function arrayManipulation in the editor below.

arrayManipulation has the following parameters:

int n - the number of elements in the array
int queries[q][3] - a two dimensional array of queries where each queries[i] contains three integers, a, b, and k.

Returns

int - the maximum value in the resultant array

Input Format

The first line contains two space-separated integers and , the size of the array and the number of operations.
Each of the next lines contains three space-separated integers , and , the left index, right index and summand.

Constraints

Sample Input

Sample Output

Explanation

After the first update the list is 100 100 0 0 0.
After the second update list is 100 200 100 100 100.
After the third update list is 100 200 200 200 100.

The maximum value is .

#include <bits/stdc++.h>

using namespace std;

string ltrim(const string &);
string rtrim(const string &);
vector<string> split(const string &);
const int N=1e7+10;
long long int arr[N];
/*
 * Complete the 'arrayManipulation' function below.
 *
 * The function is expected to return a LONG_INTEGER.
 * The function accepts following parameters:
 *  1. INTEGER n
 *  2. 2D_INTEGER_ARRAY queries
 */

long arrayManipulation(int n, vector<vector<int>> queries) {
   long long ans=0;
   int quer=queries.size();
   long long int t=queries.size();
   long long start=0;
    while(start<t){
        long long int a,b,k;
        a=queries[start][0];
        b=queries[start][1];
        k=queries[start][2];
        arr[a]+=k;
        arr[b+1]-=k;
        start++;
    }
    for(int i=1; i<=n; i++){
        arr[i]+=arr[i-1];
        ans=max(arr[i],ans);
    }
    
    return ans;
}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    string first_multiple_input_temp;
    getline(cin, first_multiple_input_temp);

    vector<string> first_multiple_input = split(rtrim(first_multiple_input_temp));

    int n = stoi(first_multiple_input[0]);

    int m = stoi(first_multiple_input[1]);

    vector<vector<int>> queries(m);

    for (int i = 0; i < m; i++) {
        queries[i].resize(3);

        string queries_row_temp_temp;
        getline(cin, queries_row_temp_temp);

        vector<string> queries_row_temp = split(rtrim(queries_row_temp_temp));

        for (int j = 0; j < 3; j++) {
            int queries_row_item = stoi(queries_row_temp[j]);

            queries[i][j] = queries_row_item;
        }
    }

    long result = arrayManipulation(n, queries);

    fout << result << "\n";

    fout.close();

    return 0;
}

string ltrim(const string &str) {
    string s(str);

    s.erase(
        s.begin(),
        find_if(s.begin(), s.end(), not1(ptr_fun<int, int>(isspace)))
    );

    return s;
}

string rtrim(const string &str) {
    string s(str);

    s.erase(
        find_if(s.rbegin(), s.rend(), not1(ptr_fun<int, int>(isspace))).base(),
        s.end()
    );

    return s;
}

vector<string> split(const string &str) {
    vector<string> tokens;

    string::size_type start = 0;
    string::size_type end = 0;

    while ((end = str.find(" ", start)) != string::npos) {
        tokens.push_back(str.substr(start, end - start));

        start = end + 1;
    }

    tokens.push_back(str.substr(start));

    return tokens;
}