Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
s=list(map(ord,list(input())))
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i==82:R[-1]+=1
  elif i==71:G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if 82 not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==82:ans-=1
    elif 71 not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==71:ans-=1
    else:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==66:ans-=1
print(ans)


Fixed submission:
n=int(input())
s=input()
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i=="R":R[-1]+=1
  elif i=="G":G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if "R" not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="R":ans-=1
    if "G" not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="G":ans-=1
    if "B" not in [s[i],s[j]]:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="B":ans-=1
print(ans)

Buggy python submission (verdict: Runtime Error):
n=int(input())
s=list(map(ord,input().split()))
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i==82:R[-1]+=1
  elif i==71:G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if 82 not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==82:ans-=1
    elif 71 not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==71:ans-=1
    else:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==66:ans-=1
print(ans)

Fixed submission:
n=int(input())
s=input()
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i=="R":R[-1]+=1
  elif i=="G":G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if "R" not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="R":ans-=1
    if "G" not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="G":ans-=1
    if "B" not in [s[i],s[j]]:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="B":ans-=1
print(ans)

Buggy python submission (verdict: Runtime Error):
n=int(input())
s=list(map(ord,input().split()))
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i==82:R[-1]+=1
  elif i=="71":G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if 82 not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==82:ans-=1
    elif 71 not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==71:ans-=1
    else:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]==66:ans-=1
print(ans)


Fixed submission:
n=int(input())
s=input()
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i=="R":R[-1]+=1
  elif i=="G":G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if "R" not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="R":ans-=1
    if "G" not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="G":ans-=1
    if "B" not in [s[i],s[j]]:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="B":ans-=1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n=int(input())
s=input()
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i=="R":R[-1]+=1
  elif i=="G":G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if "R" not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="R":ans-=1
    if "G" not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="G":ans-=1
    if "B" not in [s[i],s[j]]:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="B":ans-=1
print(ans)

Fixed submission:
n=int(input())
s=input()
R=[0]
G=[0]
B=[0]
for i in s:
  R.append(R[-1])
  G.append(G[-1])
  B.append(B[-1])
  if i=="R":R[-1]+=1
  elif i=="G":G[-1]+=1
  else:B[-1]+=1
ans=0
for i in range(n-2):
  for j in range(i+1,n-1):
    if s[i]==s[j]:continue
    if "R" not in [s[i],s[j]]:
      ans+=R[-1]-R[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="R":ans-=1
    if "G" not in [s[i],s[j]]:
      ans+=G[-1]-G[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="G":ans-=1
    if "B" not in [s[i],s[j]]:
      ans+=B[-1]-B[j]
      if j+(j-i)<n:
        if s[j+(j-i)]=="B":ans-=1
print(ans)