Buggy python submission (verdict: Runtime Error):
n = int(input())
a = list(map(int, input().split()))

left = 0
right = 2
p = a[0]
q = a[1]
res_left = abs(p - q)
r = a[2]
s: int = sum(a[3:])
res_right = abs(r - s)
result = max(p,q,r,s) - min(p,q,r,s)

for i in range(2, n - 2):
    q += a[i]
    r -= a[i]
    if i == right:
        right += 1
        r += a[i + 1]
        s -= a[i + 1]
    res_left = abs(p - q)
    res_right = abs(r - s)
    temp = left + 1
    x = p
    y = q
    while temp < i:
        x += a[temp]
        y -= a[temp]
        if abs(x - y) < res_left:
            left = temp
            p = x
            q = y
            res_left = abs(x - y)
        if x >= y:
            break
        temp += 1
    temp = right + 1
    x = r
    y = s
    while temp < n - 1:
        x += a[temp]
        y -= a[temp]
        if abs(x - y) < res_right:
            right = temp
            r = x
            s = y
            res_right = abs(x - y)
        if x >= y:
            break
        temp += 1
    temp_res = max(p, q, r, s) - min(p, q, r, s)
    if temp_res < result:
        result = temp_res

print(result)

Fixed submission:
from functools import reduce

n = int(input())
a = list(map(int, input().split()))

left = 0
right = 2
p = a[0]
q = a[1]
r = a[2]
s = reduce(lambda x, y: x + y, a[3:])
temp = right + 1
res_right = abs(s - r)
x = r
y = s
while temp < n - 1:
    x += a[temp]
    y -= a[temp]
    if abs(x - y) < res_right:
        right = temp
        r = x
        s = y
        res_right = abs(x - y)
    if x >= y:
        break
    temp += 1
result = max(p,q,r,s) - min(p,q,r,s)

for i in range(2, n - 2):
    q += a[i]
    r -= a[i]
    if i == right:
        right += 1
        r += a[i + 1]
        s -= a[i + 1]
    res_left = abs(p - q)
    res_right = abs(r - s)
    temp = left + 1
    x = p
    y = q
    while temp < i:
        x += a[temp]
        y -= a[temp]
        if abs(x - y) < res_left:
            left = temp
            p = x
            q = y
            res_left = abs(x - y)
        if x >= y:
            break
        temp += 1
    temp = right + 1
    x = r
    y = s
    while temp < n - 1:
        x += a[temp]
        y -= a[temp]
        if abs(x - y) < res_right:
            right = temp
            r = x
            s = y
            res_right = abs(x - y)
        if x >= y:
            break
        temp += 1
    temp_res = max(p, q, r, s) - min(p, q, r, s)
    if temp_res < result:
        result = temp_res

print(result)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
a = list(map(int, input().split()))

l = 1
r = 3
w = a[0]
x = a[1]
y = a[2]
z = sum(a[3:])
result = max(w,x,y,z) - min(w,x,y,z)

for i in range(2, n - 1):
    if r == i:
        r += 1
    w = sum(a[:l])
    x = sum(a[l:i])
    res_l = abs(w - x)
    y = sum(a[i:r])
    z = sum(a[r:])
    res_r = abs(y - z)
    temp = l
    while temp < i:
        p = sum(a[:temp])
        q = sum(a[temp:i])
        sum_temp = abs(q - p)
        if sum_temp < res_l:
            res_l = sum_temp
            l = temp
            w = p
            x = q
        if p >= q:
            break
        temp += 1
    temp = r
    while temp < n:
        p = sum(a[i:temp])
        q = sum(a[temp:])
        sum_temp = abs(q - p)
        if sum_temp < res_r:
            res_r = sum_temp
            r = temp
            y = p
            z = q
        if p >= q:
            break
        temp += 1
    temp_res = max(w,x,y,z) - min(w,x,y,z)
#    print(temp_res, w, x, y, z, l, i, r)
    if temp_res < result:
        result = temp_res

print(result)

Fixed submission:
from functools import reduce

n = int(input())
a = list(map(int, input().split()))

left = 0
right = 2
p = a[0]
q = a[1]
r = a[2]
s = reduce(lambda x, y: x + y, a[3:])
temp = right + 1
res_right = abs(s - r)
x = r
y = s
while temp < n - 1:
    x += a[temp]
    y -= a[temp]
    if abs(x - y) < res_right:
        right = temp
        r = x
        s = y
        res_right = abs(x - y)
    if x >= y:
        break
    temp += 1
result = max(p,q,r,s) - min(p,q,r,s)

for i in range(2, n - 2):
    q += a[i]
    r -= a[i]
    if i == right:
        right += 1
        r += a[i + 1]
        s -= a[i + 1]
    res_left = abs(p - q)
    res_right = abs(r - s)
    temp = left + 1
    x = p
    y = q
    while temp < i:
        x += a[temp]
        y -= a[temp]
        if abs(x - y) < res_left:
            left = temp
            p = x
            q = y
            res_left = abs(x - y)
        if x >= y:
            break
        temp += 1
    temp = right + 1
    x = r
    y = s
    while temp < n - 1:
        x += a[temp]
        y -= a[temp]
        if abs(x - y) < res_right:
            right = temp
            r = x
            s = y
            res_right = abs(x - y)
        if x >= y:
            break
        temp += 1
    temp_res = max(p, q, r, s) - min(p, q, r, s)
    if temp_res < result:
        result = temp_res

print(result)