ACM-ICPC Problem Setting Best Practices

Overview

Comprehensive guidance for creating high-quality algorithm competition problems, covering the full workflow from idea conception to publication.

When to Use

• Creating problems for ACM-ICPC, CCPC, Codeforces, or similar contests
• Writing problem statements with LaTeX
• Generating test data using testlib
• Setting up validators and checkers
• Organizing algorithm competitions

Quick Reference

Core Principles

Problem Quality

• Original idea - No duplicates or trivial enhancements
• Clear statement - Every concept defined, no ambiguity
• Complete constraints - All variable ranges specified
• Strong samples - Catch wrong interpretations

Data Quality

• Edge cases - Min/max values, boundary conditions
• Diverse constructions - Random + handcrafted
• Format compliance - Linux line endings, no trailing whitespace

Platform-Specific

• Polygon - Integrated workflow for teams
• Codeforces - Requires 5-25 rated contests
• Luogu - Requires competition awards

Red Flags - STOP

Essential Code

testlib Generator

#include "testlib.h"
int main(int argc, char* argv[]) {
    registerGen(argc, argv, 1);
    int n = opt<int>("n");
    vector<int> a(n);
    for (int i = 0; i < n; i++)
        a[i] = rnd.next(1, 1000000);
    println(n);
    println(a);
}

Basic Checker

#include "testlib.h"
int main(int argc, char* argv[]) {
    registerTestlibCmd(argc, argv);
    int jans = ans.readInt();
    int pans = ouf.readInt();
    if (pans == jans) quitf(_ok, "%d", pans);
    else quitf(_wa, "expected %d, found %d", jans, pans);
}

References

• OI Wiki - Problem Setting
• testlib Documentation
• Polygon Platform