1957D - A BIT of an Inequality - CodeForces Solution

for _ in range(int(input())):
    n = int(input())
    a = [*map(int, input().split())]
    dp0 = [1] * 31
    dp1 = [0] * 31
    pre0 = [0] * 31
    pre1 = [0] * 31
    ans = res = 0
    for v in a:
        m = v.bit_length() - 1
        pre0[m] += dp0[m]
        pre1[m] += dp1[m]
        res ^= v
        for i in range(31):
            if res & (1 << i):
                dp1[i] += 1
                ans += pre1[i]
            else:
                dp0[i] += 1
                ans += pre0[i]
    print(ans)