[Vssue]1005.K次取反后最大化的数组和.md

[youngyangyang04]

https://www.programmercarl.com/1005.K%E6%AC%A1%E5%8F%96%E5%8F%8D%E5%90%8E%E6%9C%80%E5%A4%A7%E5%8C%96%E7%9A%84%E6%95%B0%E7%BB%84%E5%92%8C.html

[Du1in9]

class Solution {
    public int largestSumAfterKNegations(int[] A, int K) {
        List<Integer> B = new ArrayList<>();
        for (int x : A) B.add(x);
        Collections.sort(B, (a, b) -> Integer.compare(Math.abs(b), Math.abs(a)));

        for (int i = 0; i < B.size(); i++) {
            if (B.get(i) < 0 && K > 0) {
                B.set(i, -B.get(i));
                K--;
            }
        }
        for(int i = 0; i < K; i++){
            B.set(B.size() - 1, -B.getLast());
        }
        int sum = 0;
        for (int x : B) sum += x;
        return sum;
    }
}

[rusthx]

class Solution {
    public int largestSumAfterKNegations(int[] nums, int k) {
        Arrays.sort(nums);
        int minNum=Integer.MAX_VALUE;
        int ans=0;
        for(int num:nums){
            if(num<0&&k>0){
                ans-=num;
                k--;
                minNum=Math.min(minNum,-num);
            }
            else {
                ans+=num;
                minNum=Math.min(minNum,num);
            }
        }

        return k%2==0? ans:ans-2*minNum;
    }
}