Why is this loop running infinitely?

Question

#include <bits/stdc++.h>
using namespace std;
void BookAllocation(vector<int> &v, int n) {
  int Sum = 0, sum = 0, k = 1;
  vector MX(k);
  for (int i = 0; i < n - 1; i++) {
    sum += v[i];
    for (int j = i + 1; j < n; i++) {  
      Sum += v[j];
    }
    k = max(Sum, sum);
    MX.push_back(k);
    k = 0;
    Sum = 0;
  }
  int size = MX.size();
  int Ans;
  for (int i = 0; i < size; i++) {
    Ans = min(MX[i], Ans);
  }
  cout << Ans;
}
int main() {
  int n = 4;
  vector v(n);
  for (int i = 0; i < n; i++) {
    cin >> v[i];
  }
  BookAllocation(v, n); // i'm just doing some book allocation question from leet code
  return 0;
}

Answer 1

Your program will never end due to this loop:

    for (int j = i + 1; j < n; i++) {
      Sum += v[j];
    }

Neither j or n are updated if true the first time. Thus endless loop.

Maybe you wanted:

    for (int j = i + 1; j < n; ++j) {
      Sum += v[j];
    }

Answer 2

please try this

#include <iostream>
#include <vector>

void BookAllocation(std::vector<int> &v, int n) {
  int Sum = 0, sum = 0, k = 1;
 std:: vector<int> MX(k);
  for (int i = 0; i < n - 1; i++) {
    sum += v.at(i);
    for (int j = i + 1; j < n; j++) {//notce j++ as @BO R mentioned
      Sum += v.at(j);
    }
    k = max(Sum, sum);
    MX.push_back(k);
    k = 0;
    Sum = 0;
  }
  int size = (int) MX.size(); // needs explicit cast because by default it returns uint
  int Ans;
  for (int i = 0; i < size; i++) {
    Ans = min(MX.at(i), Ans);
  }
  std::cout << Ans;
}
int main() {
  int n = 4;
  std::vector<int> v(n);
  for (int i = 0; i < n; i++) {
    cin >> v.at(i);
  }
  BookAllocation(v, n); // i'm just doing some book allocation question from leet code
  return 0;
}