algo

Why algo

You know the problem. You know the algorithm. But you’re spending 20 minutes on priority_queue<pair<ll,int>, vector<pair<ll,int>>, greater<>> and for (int i = 0; i < n; i++) cin >> a[i].

algo handles the boilerplate so you can focus on the algorithm.

Get started Install, compile, run.

Language tour Learn algo through worked examples.

Guides I/O, collections, graphs, DP, and C++ interop.

Reference Syntax, types, builtins, and stdlib.

What it looks like

input:
    n: int
    a: [int][n]
sort(a)
println lower(a, 5)

Compiles to:

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
    cin.tie(nullptr)->sync_with_stdio(false);
    int n; cin >> n;
    vector<int> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];
    sort(a.begin(), a.end());
    cout << (int)(lower_bound(a.begin(), a.end(), 5) - a.begin());
    cout << "\n";
    return 0;
}

What you get

Built-in algorithms - dijkstra, BFS, segment trees, DSU, LCA, bipartite matching, and more. Call them as functions, get the struct emitted only with the methods you use.

g = wgraph(n, undirected=true)
d = g.dijkstra(0).dist

DP blocks - declare dimensions, base cases, and transitions. The compiler handles the loops and initialization.

dp[i: 0..n, w: 0..W] -> int, maximize:
    base: dp[0][w] = 0
    <- dp[i-1][w]
    guard w >= weights[i]
    <- dp[i-1][w - weights[i]] + values[i]

Pattern matching - destructure structs and tuples with guards.

match node:
    case Node((a, b), w) where a + b == w:
        answer = a * b
    default:
        answer = a + b + w

Clean output - no hidden runtime, no template boilerplate. The generated C++ is readable, debuggable, and submittable.