Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = 0
for i in range(len(r)):
    for j in range(len(g)):
        for k in range(len(b)):
            temp = [r[i], g[j], b[k]]
            temp.sort()

            if temp[1]-temp[0] != temp[2]-temp[1]:
                cnt += 1
                if temp[2] == b[k] and temp[1]-temp[0] < temp[2]-temp[1]:
                    cnt = cnt+len(b)-1-k
                    break
print(cnt)


Fixed submission:
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = len(r)*len(g)*len(b)
for i in range(N):
    for j in range(i+1, N):
        k = 2*j-i
        if k < N and S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
            cnt -= 1
print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = 0
for i in range(len(r)):
    for j in range(len(g)):
        for k in range(len(b)):
            temp = [r[i], g[j], b[k]]
            temp.sort()

            if temp[1]-temp[0] != temp[2]-temp[1]:
                cnt+=1
print(cnt)


Fixed submission:
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = len(r)*len(g)*len(b)
for i in range(N):
    for j in range(i+1, N):
        k = 2*j-i
        if k < N and S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
            cnt -= 1
print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = 0
for i in range(len(r)):
    for j in range(len(g)):
        for k in range(len(b)):
            x = min(r[i], g[j], b[k])
            y = max(r[i], g[j], b[k])
            if r[i] != x and r[i] != y:
                if r[i]-x != y-r[i]:
                    cnt += 1
            elif g[j] != x and g[j] != y:
                if g[j]-x != y-g[j]:
                    cnt += 1
            else:
                if b[k]-x != y-b[k]:
                    cnt += 1
print(cnt)

Fixed submission:
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = len(r)*len(g)*len(b)
for i in range(N):
    for j in range(i+1, N):
        k = 2*j-i
        if k < N and S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
            cnt -= 1
print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = 0
for i in range(len(r)):
    for j in range(len(g)):
        for k in range(len(b)):
            x=min(r[i], g[j], b[k])
            y=max(r[i], g[j], b[k])
            if r[i] != x and r[i] != y:
                if r[i]-x != y-r[i]:
                    cnt += 1
            elif g[j] != x and g[j] != y:
                if g[j]-x != y-g[j]:
                    cnt += 1
            else:
                if b[k]-x != y-b[k]:
                    cnt += 1
print(cnt)


Fixed submission:
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = len(r)*len(g)*len(b)
for i in range(N):
    for j in range(i+1, N):
        k = 2*j-i
        if k < N and S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
            cnt -= 1
print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = 0
for i in range(len(r)):
    for j in range(len(g)):
        for k in range(len(b)):
            if r[i] != min(r[i], g[j], b[k]) and r[i] != max((r[i], g[j], b[k])):
                if r[i]-min(r[i], g[j], b[k]) != max((r[i], g[j], b[k]))-r[i]:
                    cnt += 1
            elif g[j] != min(r[i], g[j], b[k]) and g[j] != max((r[i], g[j], b[k])):
                if g[j]-min(r[i], g[j], b[k]) != max((r[i], g[j], b[k]))-g[j]:
                    cnt += 1
            else:
                if b[k]-min(r[i], g[j], b[k]) != max((r[i], g[j], b[k]))-b[k]:
                    cnt += 1
print(cnt)


Fixed submission:
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = len(r)*len(g)*len(b)
for i in range(N):
    for j in range(i+1, N):
        k = 2*j-i
        if k < N and S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
            cnt -= 1
print(cnt)

Buggy python submission (verdict: Time Limit Exceeded):
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())

# print(N, S)
cnt = 0
for i in range(N):
    for j in range(i+1, N):
        for k in range(j+1, N):
            if S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
                if j-i != k-j:
                    cnt += 1
print(cnt)


Fixed submission:
from sys import stdin
import sys

# A, B, C = [int(x) for x in stdin.readline().rstrip().split()]
# A,B = [int(x) for x in stdin.readline().rstrip().split()]
# U = input().split()
# A, B = [str(x) for x in stdin.readline().rstrip().split()]
N = int(input())
S = list(input())
r = []
g = []
b = []
for i in range(N):
    if S[i] == 'R':
        r.append(i+1)
    elif S[i] == 'G':
        g.append(i+1)
    else:
        b.append(i+1)
# print(r)
# print(g)
# print(b)
cnt = len(r)*len(g)*len(b)
for i in range(N):
    for j in range(i+1, N):
        k = 2*j-i
        if k < N and S[i] != S[j] and S[i] != S[k] and S[j] != S[k]:
            cnt -= 1
print(cnt)