2026/05/11

[LeetCode] 278 First Bad Version

二分搜真的很難= ="

index從1開始又要怎麼處理?

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// The API isBadVersion is defined for you.
// bool isBadVersion(int version);

class Solution {
public:
  int firstBadVersion(int N) {
    int left = 1;
    int right = N;
    int ans = N;
    while (left <= right) {
      int mid = left + (right - left) / 2;
      if (!isBadVersion(mid)) {
        left = mid + 1;
      }
      else {
        ans = mid;
        right = mid - 1;
      }
    }
    return ans;
  }
};
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