网易雷火 4.26 笔试真题

import sys
input = sys.stdin.readline

MOD = 10 ** 9 + 7
INV2 = (MOD + 1) // 2

def solve(a):
    s = 0
    sq = 0
    for x in a:
        xm = x % MOD
        s = (s + xm) % MOD
        sq = (sq + xm * xm) % MOD
    return (s * s % MOD - sq + MOD) % MOD * INV2 % MOD

T = int(input())
results = []
for _ in range(T):
    n = int(input())
    a = list(map(int, input().split()))
    results.append(str(solve(a)))
print('\n'.join(results))

import sys
from collections import OrderedDict
input = sys.stdin.readline

n, m, k = map(int, input().split())
t = list(map(int, input().split()))
cacheable = [False] + [ti == 1 for ti in t]

opened = OrderedDict()
cache = OrderedDict()

for _ in range(m):
    parts = input().split()
    op, x = parts[0], int(parts[1])
    if op == "open":
        if x in opened:
            del opened[x]
            opened[x] = True
        elif x in cache:
            del cache[x]
            opened[x] = True
        else:
            opened[x] = True
    else:
        if x not in opened:
            continue
        del opened[x]
        if cacheable[x]:
            if len(cache) >= k:
                cache.popitem(last=False)
            cache[x] = True

out = []
out.append(' '.join(str(x) for x in opened) if opened else 'EMPTY')
out.append(' '.join(str(x) for x in cache) if cache else 'EMPTY')
print('\n'.join(out))

import sys
input = sys.stdin.readline

def solve():
    n, m, w = map(int, input().split())
    sites = []
    for _ in range(n):
        parts = list(map(int, input().split()))
        a, k = parts[0], parts[1]
        clues = list(map(int, input().split()))
        mask = 0
        for c in clues:
            mask |= 1 << (c - 1)
        sites.append((a, mask))

    pw3 = [1] * (w + 1)
    for i in range(1, w + 1):
        pw3[i] = pw3[i - 1] * 3
    total = pw3[w]

    INF = float('inf')
    f = [INF] * total
    f[0] = 0

    for cost, mask in sites:
        for s in range(total - 1, -1, -1):
            if f[s] < INF and f[s] + cost <= m:
                ns = s
                tmp = mask
                while tmp:
                    j = (tmp & -tmp).bit_length() - 1
                    digit = (ns // pw3[j]) % 3
                    if digit < 2:
                        ns += pw3[j]
                    tmp &= tmp - 1
                val = f[s] + cost
                if val < f[ns]:
                    f[ns] = val

    best = 0
    for s in range(total):
        if f[s] <= m:
            cnt = 0
            tmp = s
            for _ in range(w):
                if tmp % 3 == 2:
                    cnt += 1
                tmp //= 3
            if cnt > best:
                best = cnt
    return best

T = int(input())
results = []
for _ in range(T):
    results.append(str(solve()))
print('\n'.join(results))

import sys
input = sys.stdin.readline

N, M, X, Y = map(int, input().split())

red_state = {}
for _ in range(N):
    parts = input().split()
    red_state[parts[0]] = parts[1] == '1'

group_members = {}
for _ in range(M):
    parts = input().split()
    name, num = parts[0], int(parts[1])
    group_members[name] = parts[2:2 + num]

btn_order = []
btn_binds = {}
for _ in range(X):
    parts = input().split()
    name, num = parts[0], int(parts[1])
    btn_order.append(name)
    btn_binds[name] = set(parts[2:2 + num])

panel_order = []
panel_btns = {}
for _ in range(Y):
    parts = input().split()
    name, num = parts[0], int(parts[1])
    panel_order.append(name)
    panel_btns[name] = parts[2:2 + num]

def is_active(name):
    if name in red_state:
        return red_state[name]
    if name in group_members:
        return any(red_state.get(r, False) for r in group_members[name])
    return False

def btn_active(btn):
    return any(is_active(b) for b in btn_binds.get(btn, set()))

def panel_active(panel):
    return any(btn_active(b) for b in panel_btns.get(panel, []))

S = int(input())
results = []
for _ in range(S):
    parts = input().split()
    op = parts[0]
    if op == "Ask":
        results.append("YES" if btn_active(parts[1]) else "NO")
    elif op == "AskUI":
        results.append("YES" if panel_active(parts[1]) else "NO")
    else:
        before = {p: panel_active(p) for p in panel_order}
        if op == "Show":
            if parts[1] in red_state:
                red_state[parts[1]] = True
        elif op == "Hide":
            if parts[1] in red_state:
                red_state[parts[1]] = False
        elif op == "Remove":
            btn, target = parts[1], parts[2]
            if btn in btn_binds:
                btn_binds[btn].discard(target)
        elif op == "Bind":
            btn, target = parts[1], parts[2]
            if btn in btn_binds and target not in btn_binds[btn]:
                btn_binds[btn].add(target)
        for p in panel_order:
            if before[p] and not panel_active(p):
                results.append(p)

print('\n'.join(results))