docker_space/frontier_cs_3/bench_interactor.cpp

// Benchmark testlib readInt speed
#include <bits/stdc++.h>
#include <chrono>
using namespace std;

// Simulate ouf.readInt() with the same testlib approach
// testlib reads from stdin character by character

int main() {
    // Generate 10M integers to a file, then time reading them
    int N = 10000000;

    // Generate
    {
        FILE* f = fopen("/tmp/bench_input.txt", "w");
        mt19937 rng(42);
        for (int i = 0; i < N; i++) {
            if (i) fprintf(f, " ");
            fprintf(f, "%d", (int)(rng() % 100000) + 1);
        }
        fprintf(f, "\n");
        fclose(f);
    }

    // Read using getchar (similar to testlib)
    {
        FILE* f = fopen("/tmp/bench_input.txt", "r");
        auto start = chrono::steady_clock::now();
        long long sum = 0;
        for (int i = 0; i < N; i++) {
            int c = fgetc(f);
            while (c < '0' || c > '9') { c = fgetc(f); if (c == EOF) break; }
            int x = 0;
            while (c >= '0' && c <= '9') { x = x*10+(c-'0'); c = fgetc(f); }
            sum += x;
        }
        auto end = chrono::steady_clock::now();
        double elapsed = chrono::duration<double>(end - start).count();
        printf("fgetc: Read %d ints in %.3fs (%.1f M/s), sum=%lld\n", N, elapsed, N/elapsed/1e6, sum);
        fclose(f);
    }

    // Read using scanf (testlib uses InStream which is similar)
    {
        FILE* f = fopen("/tmp/bench_input.txt", "r");
        auto start = chrono::steady_clock::now();
        long long sum = 0;
        for (int i = 0; i < N; i++) {
            int x;
            fscanf(f, "%d", &x);
            sum += x;
        }
        auto end = chrono::steady_clock::now();
        double elapsed = chrono::duration<double>(end - start).count();
        printf("fscanf: Read %d ints in %.3fs (%.1f M/s), sum=%lld\n", N, elapsed, N/elapsed/1e6, sum);
        fclose(f);
    }

    return 0;
}