mod arr;
struct Solution {}

impl Solution {
    pub fn triangle_number(nums: Vec<i32>) -> i32 {
        if nums.len() < 3 {
            return 0;
        }
        let mut nums = nums;
        nums.sort();
        let mut ans = 0;
        for i in 0..nums.len() - 2 {
            let mut r = i + 2;
            for l in i + 1..nums.len() - 1 {
                while r < nums.len() && nums[i] + nums[l] > nums[r] {
                    r += 1;
                }

                ans += ((r - l) as i32 - 1).max(0);
            }
        }
        ans
    }
}

fn main() {
    let arr = vec![7, 0, 0, 0];
    println!("{}", Solution::triangle_number(arr));
}