# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
1272421 | Art | Relativnost (COCI15_relativnost) | C++20 | 0 ms | 0 KiB |
// - Art -
#pragma GCC optimize("O3,unroll-loops") // O2
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#define el cout << '\n'
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define REV(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)
#define REP(i, c) for (int i = 0, _c = (c); i < _c; ++i)
const int N = 1e5 + 7;
const int MOD = 1e4 + 7;
const int BLOCKSIZE = 578;
const int NUMBLOCK = N / BLOCKSIZE + 7;
using namespace std;
int a[N], b[N];
namespace naive {
int dp[N][22];
void solve(int n, int k) {
int q;
cin >> q;
while (q--) {
int id, na, nb;
cin >> id >> na >> nb;
na %= MOD;
nb %= MOD;
a[id] = na;
b[id] = nb;
dp[0][0] = 1;
FOR (i, 1, n) REP (j, k) {
dp[i][j] = dp[i - 1][j] * b[i] % MOD;
if (j > 0) {
dp[i][j] = (dp[i][j] + dp[i - 1][j - 1] * a[i]) % MOD;
}
}
int tot = 1;
FOR (i, 1, n) {
tot = (a[i] + b[i]) * tot % MOD;
}
REP (i, k) {
tot = (tot - dp[n][i] + MOD) % MOD;
}
cout << tot, el;
}
}
}
int inverse(int a) {
int b = MOD - 2, res = 1;
while (b) {
if (b & 1) {
res = res * a % MOD;
}
a = a * a % MOD;
b >>= 1;
}
return res;
}
namespace blocksqrt {
int block[N];
int dp[NUMBLOCK][22];
int pre[NUMBLOCK][22];
void solve(int n, int k) {
int tot = 1;
REP (i, n) {
block[i] = i / BLOCKSIZE;
a[i] = a[i + 1];
b[i] = b[i + 1];
tot = (a[i] + b[i]) * tot % MOD;
}
FOR (x, 0, block[n - 1]) {
int l = x * BLOCKSIZE;
int r = min(n, l + BLOCKSIZE) - 1;
dp[x][0] = b[l];
dp[x][1] = a[l];
FOR (i, l + 1, r) REV (j, k - 1, 0) {
dp[x][j] = (dp[x][j] * b[i]) % MOD;
if (j > 0) {
dp[x][j] = (dp[x][j] + dp[x][j - 1] * a[i]) % MOD;
}
}
if (x > 0) {
REP (j, k) REP (o, j + 1) {
pre[x][j] = (pre[x][j] + pre[x - 1][o] * dp[x][j - o]) % MOD;
}
}
else {
REP (j, k) {
pre[x][j] = dp[x][j];
}
}
}
int q;
cin >> q;
while (q--) {
int id, na, nb;
cin >> id >> na >> nb;
na %= MOD;
nb %= MOD;
--id;
tot = tot * inverse(a[id] + b[id]) % MOD;
tot = tot * (na + nb) % MOD;
a[id] = na;
b[id] = nb;
int x = block[id];
int l = x * BLOCKSIZE;
int r = min(n, l + BLOCKSIZE) - 1;
memset(dp[x], 0, sizeof dp[x]);
dp[x][0] = b[l];
dp[x][1] = a[l];
FOR (i, l + 1, r) {
REV (j, k - 1, 0) {
dp[x][j] = dp[x][j] * b[i] % MOD;
if (j > 0) {
dp[x][j] = (dp[x][j] + dp[x][j - 1] * a[i]) % MOD;
}
}
}
int res = tot;
for (; x <= block[n - 1]; ++x) {
if (x > 0) {
memset(pre[x], 0, sizeof pre[x]);
REP (j, k) {
REP (o, j + 1) {
pre[x][j] = (pre[x][j] + pre[x - 1][o] * dp[x][j - o]) % MOD;
}
}
}
else {
REP (j, k) {
pre[x][j] = dp[x][j];
}
}
}
REP (j, k) {
res = (res - pre[block[n - 1]][j] + MOD) % MOD;
}
cout << res, el;
}
}
}
struct SegmentTree {
int n, k;
vector<vector<int>> st;
SegmentTree(int _n, int _k) {
n = _n; k = _k;
st.assign(4 * _n + 7, vector<int>(_k + 7, 0));
build(1, 1, n);
}
void build(int id, int l, int r) {
if (l == r) {
st[id][0] = b[l];
st[id][1] = a[l];
return;
}
int m = (l + r) / 2;
build(id * 2, l, m);
build(id * 2 + 1, m + 1, r);
REP (i, k) REP (j, i + 1) {
st[id][i] = (st[id][i] + st[id * 2][j] * st[id * 2 + 1][i - j]) % MOD;
}
}
void update(int id, int l, int r, int i) {
if (i < l || i > r) {
return;
}
if (l == r) {
st[id][0] = b[l];
st[id][1] = a[l];
return;
}
int m = (l + r) / 2;
update(id * 2, l, m, i);
update(id * 2 + 1, m + 1, r, i);
REP (i, k) {
st[id][i] = 0;
REP (j, i + 1) {
st[id][i] = (st[id][i] + st[id * 2][j] * st[id * 2 + 1][i - j]) % MOD;
}
}
}
void update(int i) {
update(1, 1, n, i);
}
};
int main() {
#define name "art"
if (fopen(name".inp", "r")) {
freopen(name".inp", "r", stdin);
freopen(name".out", "w", stdout);
}
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int n, k;
cin >> n >> k;
FOR (i, 1, n) {
cin >> a[i];
a[i] %= MOD;
}
FOR (i, 1, n) {
cin >> b[i];
b[i] %= MOD;
}
if (n <= 5000) {
naive::solve(n, k);
return 0;
}
if (n <= 5e4) {
blocksqrt::solve(n, k);
return 0;
}
int tot = 1;
FOR (i, 1, n) {
tot = (a[i] + b[i]) * tot % MOD;
}
SegmentTree seg(n, k);
int q;
cin >> q;
while (q--) {
int id, na, nb;
cin >> id >> na >> nb;
na %= MOD;
nb %= MOD;
tot = tot * inverse(a[id] + b[id]) % MOD;
tot = tot * (na + nb) % MOD;
a[id] = na;
b[id] = nb;
seg.update(id);
int res = tot;
REP (i, k) {
res = (res - seg.st[1][i] + MOD) % MOD;
}
cout << res, el;
}
// cerr << "Time elapsed: " << 1.0 * clock() / CLOCKS_PER_SEC << "s\n";
return 0;
}