暴力 + 位运算

因为总共有16个格子, 每个格子都有两种选择(点击或者不点), 因此, 总共2^16=65536种.
对于每种开关选择, 最多有16下点击. 每个点击的影响, 可以预处理得到. 通过异或位运算, 对于每个点击, 在O(1)时间里面得到影响.
因此, 时间复杂度为O(16 * 2^16)

时间复杂度

O(16 * 2^16)

Python 代码

Log2 = {(1 << i) : i for i in range(16)}
def decode(state):
    idxs = []
    idxs2 = []
    while state:
        tmp = state & (-state)
        state -= tmp
        ind = Log2[tmp]
        i, j = divmod(ind, 4)
        idxs.append((i, j))
        idxs2.append(ind)
    return idxs, idxs2

f = [0] * 16
for i in range(4):
    for j in range(4):
        ind = i * 4 + j
        val = 0
        for r in range(4):
            ind2 = r * 4 + j
            val += 1 << ind2
        for c in range(4):
            if c != j:
                ind2 = i * 4 + c
                val += 1 << ind2
        f[ind] = val

def check(idxs):
    B = A
    for idx in idxs:
        B ^= f[idx]
    return B == 0

A = 0
for i in range(4):
    for j, a in enumerate(input()):
        if a == "+":
            ind = i * 4 + j
            A += 1 << ind

ans = 17
ans_idxs =  [[-1] * 2 for _ in range(ans)]
for state in range(1 << 16):
    idxs, idxs2 = decode(state)
    if len(idxs) >= ans: continue
    if check(idxs2):
        ans = len(idxs)
        ans_idxs = idxs

print(ans)
for i in range(ans):
    for j in range(2):
        print(ans_idxs[i][j] + 1, end=" ")
    print()