Submission #2119717

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Source Code Expand

def main():
    N, M = [int(x) for x in input().strip().split()]
    if M == 0:
        return "Yes"

    tables = []
    for i in range(M):
        tables.append([int(x) for x in input().strip().split()])
    tables.sort()

    x1, x2, d = tables[0]
    stock = {x1:0}
    for _ in range(2):
        for rows in tables:
            x1, x2, d = rows
            if x1 in stock:
                if x2 in stock:
                    if stock[x2] != stock[x1] + d:
                        return "No"
                else:
                    stock[x2] = stock[x1] + d
    return "Yes"

if __name__ == '__main__':
    print(main())

Submission Info

Judge Result