解：

我假期结束了
友好提示：容易超时，可以从不同思路写

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int quickSelect(vector<int>& nums, int left, int right, int k) {
    if (left == right) return nums[left];  
    int pivot = nums[left + (right - left) / 2];
    int i = left, j = right;
    while (i <= j) {
        while (nums[i] > pivot) i++;
        while (nums[j] < pivot) j--;
        if (i <= j) swap(nums[i++], nums[j--]);
    }  
    if (left + k - 1 <= j) return quickSelect(nums, left, j, k);
    if (left + k - 1 >= i) return quickSelect(nums, i, right, k - (i - left));
    return nums[j + 1];
}
int main() {
    int n, k, f, t, m;
    cin >> n >> k >> f >> t >> m;
    vector<int> arr(n);
    arr[0] = f;
    for (int i = 1; i < n; ++i) {
        arr[i] = (arr[i-1] + t) % m;
    }   
    cout << quickSelect(arr, 0, n - 1, k) << endl;   
    return 0;
}