Find N Unique Integers Sum up to Zero
给一个数字n, 返回一个数组, 里面有n个数, 里面的数相加等于0. 这个就是观察一下奇偶规律.
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class Solution { public int[] sumZero(int n) { int[] res = new int[n]; if(n % 2 == 0){ // if even, n = 4 1 -1 2 -2 int k = 0; for(int i = 1; i <= n/2; i++){ res[k++] = i; res[k++] = -i; } } else { int k = 0; res[k] = 0; for(int i = 1; i <= n/2; i++){ res[k++] = i; res[k++] = -i; } } return res; } } |