// Always think of patterns (LCM, GCD) // Be careful of unsigned // Think of a solution that gets TLE and optimize it // Use binary search // Solve on paper first // Reverse Thinking // Monotonic stack/dequeue // EV is computed using probabilities or number of ways // E(X + Y) = E(X) + E(Y) // E(X * Y) = E(X) * E(Y) // If there's an equation, transform it into an easy one // Try not to use doubles // Don't do DP in graphs on anything rather than DAGs // Don't use the fucking "double" // READ ALL PROBLEMS