#include <iostream>
#include <vector>
using namespace std;
 
int main() {
    vector<int> numbers = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
    int n = numbers.size();
 
    vector<int> prefix(n);
    prefix[0] = numbers[0];
    for(int i = 1; i < n; i++) {
        prefix[i] = prefix[i - 1] + numbers[i];
    }
 
    int l = 3, r = 7;
    int sum;
    if(l == 0)
        sum = prefix[r];
    else
        sum = prefix[r] - prefix[l - 1];
 
    cout << "Prefix Sum [" << l << "," << r << "] = " << sum << endl;
 
    return 0;
}
 

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