Submission #2793710

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Source Code Expand

n, m = map(int, input().split())
xs = [tuple(map(int, input().split())) for _ in range(m)]

union = {x:(x, 0) for x in range(1, n+1)}
def root(n):
    if union[n][0] == n:
        return union[n]
    n1, d1 = union[n]
    n2, d2 = root(n1)
    union[n] = (n2, d2+d1)
    return union[n]

for l, r, d in xs:
    n1, d1 = root(l)
    n2, d2 = root(r)
    if n1 != n2:
        union[n2] = (n1, d + d1 - d2)
    elif d != d2 - d1:
        print('No')
        break
else:
    print('Yes')

Submission Info

Judge Result