Smallest X for Quadratic at Least K
MediumP3Coding
Given non-negative integers a, b, c and k, find the smallest non-negative integer x such that a * x^2 + b * x + c >= k. If no such x exists, return -1.
Example 1
- Input
- a = 1, b = 0, c = 0, k = 10
- Output
- 4
- Why
- 4^2 = 16 >= 10 and 3^2 = 9 < 10.
Example 2
- Input
- a = 0, b = 0, c = 5, k = 6
- Output
- -1
- Why
- The value is always 5.
Example 3
- Input
- a = 2, b = 3, c = 10, k = 5
- Output
- 0
- Why
- At x = 0 the value is already 10.
Constraints
- 0 <= a, b, c <= 10^5
- 0 <= k <= 10^9
Hints
Give it a real attempt first. Run shows which examples fail.
Saved automatically
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