Code Review (Warmup): Boolean Flag Arguments

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Code Review (Warmup): Boolean Flag Arguments

Story

What does sendEmail(user, true) actually do?

Send a welcome email? Skip validation? Run in "special mode"?

Boolean flags hide behavior behind a yes/no switch.

They make functions harder to understand, harder to test and harder to extend without adding even more flags.

Rule of thumb:

If a boolean changes behavior, it probably deserves a separate function.

Next Topic: Deep Nesting (Arrow Code)

export function combinationSum(candidates: number[], target: number, useAlternate: boolean = false): number[][] {
  candidates.sort((a, b) => a - b);
  const res: number[][] = [];
  const combo: number[] = [];

function universalBacktrack(start: number, remain: number, mode: boolean) {
    if (mode) {
      // alternate implementation path
      if (remain === 0) {
        res.push(combo.slice());
        return;
      }
      if (remain < 0) return;

for (let i = start; i < candidates.length; i++) {
        const val = candidates[i];
        // alternate behavior: don't break early, just skip values greater than remain
        if (val > remain) continue;
        combo.push(val);
        universalBacktrack(i, remain - val, mode);
        combo.pop();
      }
    } else {
      // original implementation path
      if (remain === 0) {
        res.push(combo.slice());
        return;
      }
      if (remain < 0) return;

for (let i = start; i < candidates.length; i++) {
        const val = candidates[i];
        if (val > remain) break;
        combo.push(val);
        universalBacktrack(i, remain - val, mode);
        combo.pop();
      }
    }
  }

universalBacktrack(0, target, useAlternate);
  return res;
}