6 3 -1 0 5 -2 0
[2, 2, 2]
static int[] countSigns(int[] a){int p=0,n=0,z=0;for(int x:a){if(x>0) p++; else if(x<0) n++; else z++;}return new int[]{p,n,z};}
static int[] countSigns(int[] a){int p=0,n=0,z=0;for(int x:a){if(x>0) p++; else if(x<0) n++; else z++;}return new int[]{p,n,z};}