Final Test case Generator

#include "bits/stdc++.h"
#define sp putchar_unlocked

inline int rand(int l, int r){
    static std::mt19937 rng(std::chrono::steady_clock::now().time_since_epoch().count());
    std::uniform_int_distribution<int> uid(l, r); return uid(rng);
}
inline void pr(int n){if(n<0){n=-n;putchar_unlocked('-');}int i=10;char output_buffer[10];do{output_buffer[--i]=(n%10)+'0';n/=10;}while(n);do{putchar_unlocked(output_buffer[i]);}while(++i<10);}
int main() {
    srand(time(NULL));
    int l = -10, r = 10;
    int nl = 1, nh = 500000;
    int t = 1, n;
    // pr(t);sp('\n');
    while(t--) {
        n = rand(nl, nh);
        pr(n);sp('\n');
        while(n--) {
            pr(rand(l, r));
            sp(' ');
        }
        sp('\n');
    }
}