Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = tuple([int(x) for x in input().rstrip()])
    n = len(s)
    ans = 0
    d = {}
    T = 0
    T1 = 0
    for i in range(n):
        T1 = s[n-1-i]*10**i+T
        T = T1
        t = T%mod
        if t in d:
            d[t] += 1
        else:
            d[t] = 1
    for k in d:
        if k != 0:
            ans += d[k]*(d[k]-1)//2
        else:
            ans += d[k]
    print(ans)
if __name__ == "__main__":
    main()

Fixed submission:
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    d = {}
    d[0] = 1
    ten = 1
    T = 0
    for x in reversed(s):
        T += ten*int(x)
        ten *= 10
        T %= mod
        ten %= mod
        if T in d:
            d[T] += 1
        else:
            d[T] = 1

    print(sum(i*(i-1)//2 for i in d.values()))
if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = tuple([int(x) for x in input().rstrip()])
    n = len(s)
    ans = 0
    d = {}
    T = 0
    T1 = 0
    for i in range(n):
        T1 = s[n-1-i]*10**i+T
        T = T1
        t = T%mod
        if t in d:
            d[t] += 1
        else:
            d[t] = 1
    for k in d:
        if k != 0:
            ans += d[k]*(d[k]-1)//2
        else:
            ans += d[k]
    print(ans)
if __name__ == "__main__":
    main()

Fixed submission:
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    d = {}
    d[0] = 1
    ten = 1
    T = 0
    for x in reversed(s):
        T += ten*int(x)
        ten *= 10
        T %= mod
        ten %= mod
        if T in d:
            d[T] += 1
        else:
            d[T] = 1

    print(sum(i*(i-1)//2 for i in d.values()))
if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    ans = 0
    d = {}
    T = [0]*(n+1)
    for i in range(n):
        T[i+1] = int(s[n-1-i])*10**i+T[i]
        t = T[i+1]%mod
        if t in d:
            d[t] += 1
        else:
            d[t] = 1
    for k in d:
        if k != 0:
            ans += d[k]*(d[k]-1)//2
        else:
            ans += d[k]
    print(ans)
if __name__ == "__main__":
    main()

Fixed submission:
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    d = {}
    d[0] = 1
    ten = 1
    T = 0
    for x in reversed(s):
        T += ten*int(x)
        ten *= 10
        T %= mod
        ten %= mod
        if T in d:
            d[T] += 1
        else:
            d[T] = 1

    print(sum(i*(i-1)//2 for i in d.values()))
if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    ans = 0
    d = {}
    for i in range(n):
        t = int(s[i:])%mod
        if t in d:
            d[t] += 1
        else:
            d[t] = 1
    for k in d:
        if k != 0:
            ans += d[k]*(d[k]-1)//2
        else:
            ans += d[k]
    print(ans)
if __name__ == "__main__":
    main()

Fixed submission:
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    d = {}
    d[0] = 1
    ten = 1
    T = 0
    for x in reversed(s):
        T += ten*int(x)
        ten *= 10
        T %= mod
        ten %= mod
        if T in d:
            d[T] += 1
        else:
            d[T] = 1

    print(sum(i*(i-1)//2 for i in d.values()))
if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    ans = 0
    T = [int(s[k:])%mod for k in range(n)]
    d = {}
    for t in T:
        if t in d:d[t] += 1
        else:d[t] = 1
    for k in d:
        if k != 0:
            ans += d[k]*(d[k]-1)//2
        else:
            ans += d[k]
    print(ans)
if __name__ == "__main__":
    main()

Fixed submission:
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    d = {}
    d[0] = 1
    ten = 1
    T = 0
    for x in reversed(s):
        T += ten*int(x)
        ten *= 10
        T %= mod
        ten %= mod
        if T in d:
            d[T] += 1
        else:
            d[T] = 1

    print(sum(i*(i-1)//2 for i in d.values()))
if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
def main():
    s = input().rstrip()
    n = len(s)
    ans = 0
    for l in range(4,n):
        for i in range(n-l+1):
            if int(s[i:i+l])%2019 == 0:
                ans += 1
    print(ans)
if __name__ == "__main__":
    main()

Fixed submission:
import sys
input = sys.stdin.readline
mod = 2019
def main():
    s = input().rstrip()
    n = len(s)
    d = {}
    d[0] = 1
    ten = 1
    T = 0
    for x in reversed(s):
        T += ten*int(x)
        ten *= 10
        T %= mod
        ten %= mod
        if T in d:
            d[T] += 1
        else:
            d[T] = 1

    print(sum(i*(i-1)//2 for i in d.values()))
if __name__ == "__main__":
    main()