Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    color_used = [set() for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, color_used, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    for j in adjs[i]:
        if visited[j]:
            continue
        for c in range(1, 100005):
            if c in color_used[i]:
                continue
            if c in color_used[j]:
                continue
            color_used[i].add(c)
            color_used[j].add(c)
            mi = min(i, j)
            ma = max(i, j)
            colors[(mi, ma)] = c
            break
        dfs(j, adjs, visited, color_used, colors)

if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, -1, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    c = 1
    for j in adjs[i]:
        if visited[j]:
            continue
        if c == color_used:
            c += 1
        mi = min(i, j)
        ma = max(i, j)
        colors[(mi, ma)] = c
        dfs(j, adjs, visited, c, colors)
        c += 1

if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3

import sys

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    visited = [False for i in range(n)]
    color_used = [set() for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, color_used, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    for j in adjs[i]:
        if visited[j]:
            continue
        for c in range(1, 100005):
            if c in color_used[i]:
                continue
            # if c in color_used[j]:
            #     continue
            color_used[i].add(c)
            color_used[j].add(c)
            mi = min(i, j)
            ma = max(i, j)
            colors[(mi, ma)] = c
            break
        dfs(j, adjs, visited, color_used, colors)

if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, -1, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    c = 1
    for j in adjs[i]:
        if visited[j]:
            continue
        if c == color_used:
            c += 1
        mi = min(i, j)
        ma = max(i, j)
        colors[(mi, ma)] = c
        dfs(j, adjs, visited, c, colors)
        c += 1

if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3

import sys

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    visited = [False for i in range(n)]
    color_used = [set() for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, color_used, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    for j in adjs[i]:
        if visited[j]:
            continue
        for c in range(1, 100005):
            if c in color_used[j]:
                continue
            if c in color_used[i]:
                continue
            color_used[i].add(c)
            color_used[j].add(c)
            mi = min(i, j)
            ma = max(i, j)
            colors[(mi, ma)] = c
            break
        dfs(j, adjs, visited, color_used, colors)

if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, -1, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    c = 1
    for j in adjs[i]:
        if visited[j]:
            continue
        if c == color_used:
            c += 1
        mi = min(i, j)
        ma = max(i, j)
        colors[(mi, ma)] = c
        dfs(j, adjs, visited, c, colors)
        c += 1

if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3

import sys

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    visited = [False for i in range(n)]
    color_used = [set() for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, color_used, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    for j in adjs[i]:
        if visited[j]:
            continue
        for c in range(1, 100005):
            if c in color_used[i]:
                continue
            if c in color_used[j]:
                continue
            color_used[i].add(c)
            color_used[j].add(c)
            mi = min(i, j)
            ma = max(i, j)
            colors[(mi, ma)] = c
            break
        dfs(j, adjs, visited, color_used, colors)

if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, -1, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    c = 1
    for j in adjs[i]:
        if visited[j]:
            continue
        if c == color_used:
            c += 1
        mi = min(i, j)
        ma = max(i, j)
        colors[(mi, ma)] = c
        dfs(j, adjs, visited, c, colors)
        c += 1

if __name__ == "__main__":
    main()

Buggy python submission (verdict: Time Limit Exceeded):
#!/usr/bin/env python3

import sys

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    visited = [False for i in range(n)]
    color_used = [set() for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, color_used, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    for j in adjs[i]:
        if visited[j]:
            continue
        for c in range(1, 100005):
            if c in color_used[i]:
                continue
            if c in color_used[j]:
                continue
            color_used[i].add(c)
            color_used[j].add(c)
            mi = min(i, j)
            ma = max(i, j)
            colors[(mi, ma)] = c
            break
        dfs(j, adjs, visited, color_used, colors)

if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, -1, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    c = 1
    for j in adjs[i]:
        if visited[j]:
            continue
        if c == color_used:
            c += 1
        mi = min(i, j)
        ma = max(i, j)
        colors[(mi, ma)] = c
        dfs(j, adjs, visited, c, colors)
        c += 1

if __name__ == "__main__":
    main()

Buggy python submission (verdict: Runtime Error):
#!/usr/bin/env python3

def main():
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    visited = [False for i in range(n)]
    color_used = [set() for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, color_used, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    for j in adjs[i]:
        if visited[j]:
            continue
        for c in range(1, 100005):
            if c in color_used[i]:
                continue
            if c in color_used[j]:
                continue
            color_used[i].add(c)
            color_used[j].add(c)
            mi = min(i, j)
            ma = max(i, j)
            colors[(mi, ma)] = c
            break
        dfs(j, adjs, visited, color_used, colors)

if __name__ == "__main__":
    main()


Fixed submission:
#!/usr/bin/env python3

import sys
import random

def main():
    sys.setrecursionlimit(10 ** 6)
    n = int(input())
    ranks = [0 for i in range(n)]
    adjs = [[] for i in range(n)]
    edges = []
    for i in range(n - 1):
        a, b = map(int, input().split())
        edges.append((a - 1, b - 1))
        ranks[a - 1] += 1
        ranks[b - 1] += 1
        adjs[a - 1].append(b - 1)
        adjs[b - 1].append(a - 1)

    for i in range(n):
        random.shuffle(adjs[i])
    visited = [False for i in range(n)]
    colors = {}  # (mi, ma) |-> color
    dfs(0, adjs, visited, -1, colors)

    print(max(ranks))
    for i in range(n - 1):
        a, b = edges[i]
        mi = min(a, b)
        ma = max(a, b)
        print(colors[(mi, ma)])

def dfs(i, adjs, visited, color_used, colors):
    visited[i] = True
    c = 1
    for j in adjs[i]:
        if visited[j]:
            continue
        if c == color_used:
            c += 1
        mi = min(i, j)
        ma = max(i, j)
        colors[(mi, ma)] = c
        dfs(j, adjs, visited, c, colors)
        c += 1

if __name__ == "__main__":
    main()