The Preliminary Contest for ICPC Asia Shanghai 2019
D. Counting Sequences I
暴力搜索。
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD = 1000000007;
map<vector<short>, short> m;
vector<short> vec;
void calc(int num1) {
vector<short> tmp;
if(num1)
tmp.push_back(num1);
int n = vec.size();
int cur = 1;
for(int i = 1; i < n; ++i) {
if(vec[i] != vec[i - 1]) {
tmp.push_back(cur);
cur = 1;
} else
++cur;
}
tmp.push_back(cur);
sort(tmp.begin(), tmp.end());
m[tmp]++;
}
void dfs(int last, int cur, ll pro, int sum) {
for(int i = last; i <= 3000; ++i) {
int tcur = cur + 1;
ll tpro = pro * i;
int tsum = sum + i;
if(tpro - tsum + tcur > 3000)
break;
vec.push_back(i);
calc(tpro - tsum);
if(tpro * i - (tsum + i) + (tcur + 1) <= 3000)
dfs(i, tcur, tpro, tsum);
vec.pop_back();
}
}
ll qpow(ll x, int n) {
ll res = 1;
while(n) {
if(n & 1)
res = res * x % MOD;
x = x * x % MOD;
n >>= 1;
}
return res;
}
int ans[3005], prod[3005], invprod[3005];
void Init() {
dfs(2, 0, 1, 0);
prod[0] = 1;
for(int i = 1; i <= 3000; ++i) {
prod[i] = 1ll * prod[i - 1] * i % MOD;
invprod[i] = qpow(prod[i], MOD - 2);
}
for(auto mi : m) {
ll sum = 1;
int len = 0;
for(auto vi : mi.first) {
len += vi;
sum = (sum * invprod[vi]) % MOD;
}
sum = (sum * prod[len]) % MOD;
sum = (sum * mi.second) % MOD;
ans[len] = (sum + ans[len]) % MOD;
}
ans[0] = ans[1] = 0;
}
int main() {
#ifdef Yinku
freopen("Yinku.in", "r", stdin);
#endif // Yinku
Init();
int T;
scanf("%d", &T);
while(T--) {
int n;
scanf("%d", &n);
printf("%d\n", ans[n]);
}
}
H. Luhhy's Matrix
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned int uint;
struct Matrix {
bitset<16> ma[16];
Matrix() {}
void Clear() {
for(int i = 0; i < 16; ++i)
ma[i] = 0;
}
void one() {
Clear();
for(int i = 0; i < 16; ++i)
ma[i][i] = 1;
}
Matrix operator*(const Matrix& t)const {
Matrix res;
for(int i = 0; i < 16; ++i) {
for(int k = 0; k < 16; ++k) {
if(ma[i][k])
res.ma[i] ^= t.ma[k];
}
}
return res;
}
};
stack<Matrix> Stack1, Stack2;
Matrix ProdStack1, tmp;
void Push(uint seed, uint lastans) {
seed ^= lastans;
for(int i = 0; i < 16; ++i) {
seed ^= seed * seed + 15;
for(int j = 0; j < 16; ++j)
tmp.ma[i][j] = (seed >> j) & 1;
}
Stack1.push(tmp);
ProdStack1 = tmp * ProdStack1;
}
void Pop() {
if(Stack2.empty()) {
tmp.one();
while(!Stack1.empty()) {
tmp = tmp * Stack1.top();
Stack1.pop();
Stack2.push(tmp);
}
ProdStack1.one();
}
Stack2.pop();
}
uint ans[16][16];
inline void InitAns() {
uint p17[16], p19[16];
p17[0] = 1, p19[0] = 1;
for(int i = 1; i < 16; ++i) {
p17[i] = p17[i - 1] * 17u;
p19[i] = p19[i - 1] * 19u;
}
for(int i = 0; i < 16; ++i) {
for(int j = 0; j < 16; ++j)
ans[i][j] = p17[i] * p19[j];
}
}
uint Calc() {
if(Stack1.empty() && Stack2.empty())
return 0;
tmp = ProdStack1;
if(!Stack2.empty())
tmp = tmp * Stack2.top();
uint res = 0;
for(int i = 0; i < 16; ++i) {
for(int j = 0; j < 16; ++j) {
if(tmp.ma[i][j])
res += ans[i][j];
}
}
return res;
}
inline void Read(uint &x) {
x = 0;
char ch = getchar();
while(ch < '0' || ch > '9')
ch = getchar();
while(ch >= '0' && ch <= '9')
x = (x << 3) + (x << 1) + ch - '0', ch = getchar();
}
inline void Write(uint x) {
if(x < 10)
putchar(x + '0');
else {
Write(x / 10);
putchar(x % 10 + '0');
}
}
int main() {
#ifdef Yinku
freopen("Yinku.in", "r", stdin);
#endif // Yinku
InitAns();
uint T;
Read(T);
while(T--) {
while(!Stack1.empty())
Stack1.pop();
while(!Stack2.empty())
Stack2.pop();
ProdStack1.one();
uint n, t, seed, lastans = 0;
Read(n);
for(int i = 1; i <= n; ++i) {
Read(t), Read(seed);
if(t == 1)
Push(seed, lastans);
else
Pop();
lastans = Calc();
Write(lastans);
putchar('\n');
}
}
}
unsigned short优化明显，静态stack倒是没啥用。仔细观察之后两个栈可以共用同一段内存。
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned int uint;
struct Matrix {
unsigned short ma[16];
Matrix() {}
void Clear() {
memset(ma, 0, sizeof(ma));
}
void one() {
for(int i = 0; i < 16; ++i)
ma[i] = 1 << i;
}
Matrix operator*(const Matrix& t)const {
Matrix res;
res.Clear();
for(int i = 0; i < 16; ++i) {
for(int k = 0; k < 16; ++k) {
if((ma[i] >> k) & 1)
res.ma[i] ^= t.ma[k];
}
}
return res;
}
};
const int MAXN = 50000;
int s1, s2;
Matrix Stack[50000 + 5];
Matrix ProdStack1, tmp;
void Push(uint seed, uint lastans) {
seed ^= lastans;
for(int i = 0; i < 16; ++i) {
seed ^= seed * seed + 15;
tmp.ma[i] = seed;
}
Stack[++s1] = tmp;
ProdStack1 = tmp * ProdStack1;
}
void Pop() {
if(s2 > MAXN) {
tmp.one();
while(s1 > 1) {
tmp = tmp * Stack[s1--];
Stack[--s2] = tmp;
}
--s1;
ProdStack1.one();
} else
++s2;
}
uint ans[16][16];
inline void InitAns() {
uint p17[16], p19[16];
p17[0] = 1, p19[0] = 1;
for(int i = 1; i < 16; ++i) {
p17[i] = p17[i - 1] * 17u;
p19[i] = p19[i - 1] * 19u;
}
for(int i = 0; i < 16; ++i) {
for(int j = 0; j < 16; ++j)
ans[i][j] = p17[i] * p19[j];
}
}
uint Calc() {
if(s1 == 0 && s2 > MAXN)
return 0;
tmp = ProdStack1;
if(s2 <= MAXN)
tmp = tmp * Stack[s2];
uint res = 0;
for(int i = 0; i < 16; ++i) {
for(int j = 0; j < 16; ++j) {
if((tmp.ma[i] >> j) & 1)
res += ans[i][j];
}
}
return res;
}
inline void Read(uint &x) {
x = 0;
char ch = getchar();
while(ch < '0' || ch > '9')
ch = getchar();
while(ch >= '0' && ch <= '9')
x = (x << 3) + (x << 1) + ch - '0', ch = getchar();
}
inline void Write(uint x) {
if(x < 10)
putchar(x + '0');
else {
Write(x / 10);
putchar(x % 10 + '0');
}
}
int main() {
#ifdef Yinku
freopen("Yinku.in", "r", stdin);
#endif // Yinku
InitAns();
uint T;
Read(T);
while(T--) {
s1 = 0, s2 = MAXN + 1;
ProdStack1.one();
uint n, t, seed, lastans = 0;
Read(n);
for(int i = 1; i <= n; ++i) {
Read(t), Read(seed);
if(t == 1)
Push(seed, lastans);
else
Pop();
lastans = Calc();
Write(lastans);
putchar('\n');
}
}
}
