Problem:
 Score : 300 points    Problem Statement There are N+1 towns. The i -th town is being attacked by A_i monsters.  We have N heroes. The i -th hero can defeat monsters attacking the i -th or (i+1) -th town, for a total of at most B_i monsters.  What is the maximum total number of monsters the heroes can cooperate to defeat?      Constraints  All values in input are integers.  1 \leq N \leq 10^5  1 \leq A_i \leq 10^9  1 \leq B_i \leq 10^9         Input Input is given from Standard Input in the following format:  N  A_1  A_2  ...  A_{N+1}  B_1  B_2  ...  B_N       Output Print the maximum total number of monsters the heroes can defeat.        Sample Input 1 2
3 5 2
4 5      Sample Output 1 9  If the heroes choose the monsters to defeat as follows, they can defeat nine monsters in total, which is the maximum result.   The first hero defeats two monsters attacking the first town and two monsters attacking the second town.  The second hero defeats three monsters attacking the second town and two monsters attacking the third town.        Sample Input 2 3
5 6 3 8
5 100 8      Sample Output 2 22       Sample Input 3 2
100 1 1
1 100      Sample Output 3 3

Solution (Python):
N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

count = 0
for i in range(N):
  if A[i] < B[i]:
    count += A[i]
    B[i] -= A[i]
    if A[i+1] < B[i]:
      count += A[i+1]
      A[i+1] = 0
    else:
      count += B[i]
      A[i+1] -= B[i]
  else:
    count += B[i]

print(count)

Solution (Python):
N = int(input())
An = list(map(int,input().split()))
Bn = list(map(int,input().split()))
ans=0
for b in range(len(Bn)):
    left = min(An[b],Bn[b])
    ans+=left
    An[b]-=left
    Bn[b]-=left
    right = min(An[b+1],Bn[b])
    ans+=right
    An[b+1]-=right
    Bn[b]-=right
print(ans)

Solution (Python):
def cm(a,b):
    t= a-b
    if t > 0:
        return t
    else:
        return 0

def dm(a,b):
    if a > b:
        return b
    else:
        return a
N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
res = 0 
R = min(A[0]-B[0],0)
res+= dm(A[0],B[0])

for i , j in zip(A[1:],B[1:]):
    res += dm(i,-R)
    l = cm(i,-R)
    t =  l - j
    R = min(t,0)
    res+= dm(l,j)
    
res +=  dm(A[-1],-R)

print(res)

Solution (Python):
def main():
  n = int(input())
  a = list(map(int,input().split()))
  b = list(map(int,input().split()))
  c = 0
  for i in range(n):
    if a[i] >= b[i]:
      c += b[i]
    else:
      d = b[i] -a[i]
      if a[i+1] <= d:
        c += a[i] + a[i+1]
        a[i+1] = 0
      else:
        a[i+1] -= d
        c += b[i]
  print(c)

if __name__ == '__main__':
  main()

Solution (Python):
n = int(input())
a = list(map(int,input().split()))
b = list(map(int,input().split()))
c = 0
for i in range(n):
  if a[i] >= b[i]:
    c += b[i]
  else:
    d = b[i] -a[i]
    if a[i+1] <= d:
      c += a[i] + a[i+1]
      a[i+1] = 0
    else:
      a[i+1] -= d
      c += b[i]
print(c)