1454C - Sequence Transformation - CodeForces Solution

for _ in range(int(input())):
    n = int(input())
    a = []
    c = {}
    for x in map(int, input().split()):
        if not a or a[-1] != x:
            a.append(x)
            c[x] = c.get(x, 0) + 1
    d = len(a)
    for x in c:
        d = min(d, c[x] - 1 + (a[0] != x) + (a[-1] != x))
    print(d)