QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#188925 | #7509. 01tree | zhoukangyang# | WA | 4ms | 32332kb | C++11 | 2.1kb | 2023-09-26 16:52:13 | 2023-09-26 16:52:14 |
Judging History
answer
#include<bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); ++i)
#define R(i, j, k) for(int i = (j); i >= (k); --i)
#define ll long long
#define vi vector < int >
#define sz(a) ((int) (a).size())
#define ll long long
#define ull unsigned long long
#define me(a, x) memset(a, x, sizeof(a))
using namespace std;
const int N = 1 << 19, mod = 1e9 + 7;
int qpow(int x, int y = mod - 2) {
int res = 1;
for(; y; x = (ll) x * x % mod, y >>= 1) if(y & 1) res = (ll) res * x % mod;
return res;
}
int fac[N], ifac[N], inv[N];
void init(int x) {
fac[0] = ifac[0] = inv[1] = 1;
L(i, 2, x) inv[i] = (ll) (mod - mod / i) * inv[mod % i] % mod;
L(i, 1, x) fac[i] = (ll) fac[i - 1] * i % mod, ifac[i] = (ll) ifac[i - 1] * inv[i] % mod;
}
int C(int x, int y) {
return x < y || y < 0 ? 0 : (ll) fac[x] * ifac[y] % mod * ifac[x - y] % mod;
}
int n;
char s[N], t[N];
vi e[N];
int scnt[N], snon[N];
int tcnt[N], tnon[N];
int col[N];
void dfs(int x, int fa) {
if(col[x]) {
if(s[x] != '?')
s[x] ^= 1;
if(t[x] != '?')
t[x] ^= 1;
}
scnt[x] = s[x] == '1';
snon[x] = s[x] == '?';
tcnt[x] = t[x] == '1';
tnon[x] = t[x] == '?';
for(auto v : e[x]) if(v != fa) {
col[v] = col[x] ^ 1, dfs(v, x);
scnt[x] += scnt[v];
snon[x] += snon[v];
tcnt[x] += tcnt[v];
tnon[x] += tnon[v];
}
}
void Main() {
cin >> n;
L(i, 1, n - 1) {
int u, v;
cin >> u >> v;
e[u].emplace_back(v);
e[v].emplace_back(u);
}
cin >> (s + 1) >> (t + 1);
col[1] = 0, dfs(1, 0);
int ans = 0;
int qwq = tnon[1] + tcnt[1] - scnt[1];
L(i, 2, n) {
int xs = snon[1] - snon[i];
int ys = snon[i];
int xt = tnon[1] - tnon[i];
int yt = tnon[i];
int L = xs + xt;
int R = ys + yt;
int D = qwq - (yt - scnt[i] - tcnt[i]);
L(a, 0, L)
(ans += (ll) C(L, a) * C(R, qwq - a) % mod * abs(D - a) % mod) %= mod;
}
cout << ans << '\n';
L(i, 1, n) {
e[i].clear();
}
}
int main() {
init(2e5 + 7);
ios :: sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int t; cin >> t; while(t--) Main();
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 4ms
memory: 32332kb
input:
3 2 1 2 00 11 3 1 2 2 3 ??? ??? 3 1 2 2 3 ??1 0?0
output:
1 16 1
result:
ok 3 number(s): "1 16 1"
Test #2:
score: -100
Wrong Answer
time: 0ms
memory: 30360kb
input:
1000 23 1 2 1 3 1 4 2 5 5 6 4 7 3 8 4 9 8 10 8 11 8 12 1 13 7 14 10 15 7 16 7 17 5 18 18 19 12 20 9 21 21 22 6 23 00?10?0000??1?00111?010 011??1?10?01?110?0??101 6 1 2 1 3 1 4 4 5 3 6 000?10 1???01 25 1 2 2 3 2 4 4 5 5 6 2 7 4 8 5 9 7 10 8 11 11 12 5 13 11 14 3 15 6 16 14 17 1 18 4 19 6 20 4 21 5 22...
output:
121011 30 46580 3788 294 34 3177 76 998 8764 52 2 15 1744 26090 7798 1753050 0 269126 3 266 179025 62788 18 173173 23976 5565936 68064736 2018 3 657514 4384 734552 17038 744 320 15 5369078 95196 51300 23 0 2 24318 4255848 285029 371393 582439 81294 136 2312 2891476 88560 4459780 5255822 2095936 4628...
result:
wrong answer 1st numbers differ - expected: '53545', found: '121011'