Use when writing C++ competitive programming solutions for Codeforces, ICPC, or similar contests. Apply when creating XCPC solutions to ensure code follows jiangly's proven style patterns.
Proven C++ coding style from jiangly's Codeforces submissions. Focuses on safety, maintainability, and modern C++ features for competitive programming.
Core principle: Zero global pollution, zero global arrays, explicit types, modern C++.
Don't use for:
| Category | Rule | File |
|---|---|---|
| Namespace | Never using namespace std; |
no-global-namespace |
| Arrays | Zero global arrays | zero-global-arrays |
| Types | Use using i64 = long long; |
explicit-types |
| Indexing | Follow problem's natural indexing | keep-indexing-consistent |
| I/O | Disable sync, use \n |
fast-io |
| Naming | snake_case for vars, PascalCase for structs |
naming |
| Formatting | 4-space indent, K&R braces, no line compression | formatting |
| Simplicity | Prefer simple data structures | simplicity-first |
| Memory | Use in-place operations | in-place-operations |
| DFS | Use depth array, avoid parent parameter | dfs-techniques |
| Recursion | Lambda + self pattern | recursion |
| Structs | Constructor patterns, const correctness | struct-patterns |
| Operators | Overload patterns for custom types | operator-overloading |
| Helpers | chmax, ceilDiv, gcd, power, etc. | helper-functions |
| DP | Use vector, never memset |
dp-patterns |
| Modern C++ | CTAD, structured binding, C++20 features | modern-cpp-features |
#include <bits/stdc++.h>
using i64 = long long;
void solve() {
int n;
std::cin >> n;
std::vector<int> a(n);
for (int i = 0; i < n; i++) {
std::cin >> a[i];
}
std::cout << ans << "\n";
}
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int t;
std::cin >> t;
while (t--) {
solve();
}
return 0;
}
| Anti-pattern | Correct approach |
|---|---|
using namespace std; |
Use std:: prefix |
int a[100005]; global |
std::vector<int> a(n); in solve() |
#define int long long |
using i64 = long long; |
for (int i = 1; i <= n; i++) |
for (int i = 0; i < n; i++) OR keep problem's indexing |
void dfs(int u, int p) global |
Lambda with self capture |
std::endl |
Use "\n" |
if (x) do_something(); |
Always use braces |
| Over-engineered HLD + segment tree | Use binary lifting for simple path queries |
Creating e1, e2 containers |
Use vis boolean array |
| Converting 1-indexed to 0-indexed | Keep original indexing |
| Passing parent in DFS | Use depth array to check visited |
| Explicit template parameters | Use CTAD where possible |
For complete details on all rules: AGENTS.md
