Minimum sum of mountain triplets i

Array

67.2% acceptance

Feb 25, 2026

199

You are given a 0-indexed array nums of integers. A triplet of indices (i, j, k) is a mountain if: i < j < k nums[i] < nums[j] and nums[k] < nums[j] Return the minimum possible sum of a mountain triplet of nums. If no such triplet exists, return -1.

Solution

Rust

Time O(n³)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn minimum_sum(nums: Vec<i32>) -> i32 {
    let n = nums.len();
    let mut ans = i32::MAX;
    for i in 0..n {
      for j in i + 1..n {
        if nums[i] >= nums[j] { continue; }
        for k in j + 1..n {
          if nums[k] < nums[j] {
            ans = ans.min(nums[i] + nums[j] + nums[k]);
          }
        }
      }
    }
    if ans == i32::MAX { -1 } else { ans }
  }
}