模板
\[ft61
\]
试机
-
编译选项
-
extc++
-
cerr -
测速
配置
- vscode
"editor.rulers": [85],
- vim
set nu
set mouse=a
- 缺省源
#include <bits/stdc++.h>
#include <bits/extc++.h>
using namespace std; using namespace __gnu_pbds; using namespace __gnu_cxx;
#define For(i,x,y,...) for(int i=(x),##__VA_ARGS__;i<=(y);++i)
#define rFor(i,x,y,...) for(int i=(x),##__VA_ARGS__;i>=(y);--i)
#define Rep(i,x,y,...) for(int i=(x),##__VA_ARGS__;i<(y);++i)
#define pb emplace_back
#define sz(a) int((a).size())
#define all(a) (a).begin(),(a).end()
#define fi first
#define se second
#define mkp make_pair
#define mem(a,x,n) memset(a,x,sizeof(*a)*((n)+2))
typedef long long LL; typedef vector<int> Vi; typedef pair<int,int> Pii;
auto ckmax=[](auto &x,auto y) { return x<y ? x=y,true : false; };
auto ckmin=[](auto &x,auto y) { return y<x ? x=y,true : false; };
template<typename T=int>T read() { T x; cin>>x; return x; }
sfmt19937 mt(chrono::steady_clock::now().time_since_epoch().count());
int rnd(int l,int r) { return uniform_int_distribution<>(l,r)(mt); }
void MAIN() {
} signed main() {
#ifdef FS
freopen("in","r",stdin); freopen("out","w",stdout);
#endif
ios::sync_with_stdio(0);cin.tie(0);
int lft=1; while( lft-- ) {
MAIN();
}
return 0;
}
C++
__gnu_pbds
- tree
int ind;
tree<Pii,null_type,less<>,rb_tree_tag,tree_order_statistics_node_update> rbt;
rbt.insert({x,++ind});
rbt.erase(rbt.lower_bound({x,0}));
rbt.order_of_key({x,0}); // < x 的数的个数
rbt.find_by_order(x-1)->fi; // 第 x 小
(--rbt.lower_bound({x,0}))->fi; // < x 的最大数
rbt.lower_bound({x+1,0})->fi; // > x 的最小数
DP
斜率优化
求 \(\max_{i}\{kx_{i}+y_{i}\}\)。\(x_{i},y_{i},k\) 为
int
对 \((x_{i},y_{i})\) 建上凸包，查询斜率为 \(-k\) 的直线的最大截距
- 静态建
struct Vec {
LL x,y; Vec(LL x=0,LL y=0):x(x),y(y){}
bool operator < (const Vec &rhs) { return x!=rhs.x ? x<rhs.x : y<rhs.y; }
Vec operator - (const Vec &rhs) { return {x-rhs.x, y-rhs.y}; }
LL operator & (const Vec &rhs) { return x*rhs.y-y*rhs.x; } // 叉乘
};
Vec s[N]; int t = 0;
sort(all(p));
for(auto i : p) {
while( t > 1 && (s[t]-s[t-1]&i-s[t-1]) >= 0 ) --t;
s[++t] = i;
}
- 双指针查询
sort(all(q),[](int x,int y){return k[x]<k[y];});
int j = 1;
for(int i : q) {
auto f=[&](int j) { return k[j]*s[i].x+s[i].y; };
while( j < t && f(j+1) > f(j) ) ++j;
ans[i] = f(j);
}
- 二分查询
DDP
- LG4751 【模板】"动态DP"&动态树分治（加强版）
单点修改，最大权独立集
const int N = 1e6+5, inf = 0x3f3f3f3f;
int n,m,ans,a[N];
VI e[N];
struct Mat {
int a[2][2];
Mat() { memset(a,0xcf,sizeof a); }
int* operator [] (int i) { return a[i]; }
const int* operator [] (int i) const { return a[i]; }
Mat operator * (const Mat &b) const {
Mat res;
res[0][0] = max(a[0][0]+b[0][0],a[0][1]+b[1][0]),
res[0][1] = max(a[0][0]+b[0][1],a[0][1]+b[1][1]),
res[1][0] = max(a[1][0]+b[0][0],a[1][1]+b[1][0]),
res[1][1] = max(a[1][0]+b[0][1],a[1][1]+b[1][1]);
return res;
}
};
#define ls(u) t[u].ch[0]
#define rs(u) t[u].ch[1]
#define fa(u) t[u].fa
struct LCT {
struct Node { int fa,ch[2],g[2]; Mat f; } t[N];
bool nrt(int u) { return ls(fa(u))==u || rs(fa(u))==u; }
bool wh(int u) { return rs(fa(u))==u; }
void up(int u) {
t[u].f[0][0] = t[u].f[1][0] = t[u].g[0],
t[u].f[0][1] = t[u].g[1], t[u].f[1][1] = -inf;
if( ls(u) ) t[u].f = t[u].f * t[ls(u)].f;
if( rs(u) ) t[u].f = t[rs(u)].f * t[u].f;
}
void rotate(int x) {
int y = fa(x), z = fa(y), k = wh(x), w = t[x].ch[!k];
if( nrt(y) ) t[z].ch[wh(y)] = x; t[x].ch[!k] = y, t[y].ch[k] = w;
fa(w) = y, fa(y) = x, fa(x) = z, up(y);
}
void splay(int u) {
for(int fa; fa = fa(u), nrt(u); rotate(u))
if( nrt(fa) ) rotate(wh(fa)==wh(u)?fa:u);
up(u);
}
void add(int u,int v) {
t[u].g[0] += max(t[v].f[0][0],t[v].f[0][1]),
t[u].g[1] += t[v].f[0][0];
}
void del(int u,int v) {
t[u].g[0] -= max(t[v].f[0][0],t[v].f[0][1]),
t[u].g[1] -= t[v].f[0][0];
}
void access(int x) {
for(int u = x, v = 0; u; u = fa(v=u)) {
splay(u);
if( rs(u) ) add(u,rs(u));
if( (rs(u) = v) ) del(u,v);
up(u);
}
splay(x);
}
void debug() {
For(i,1,n)
cerr<<fa(i)<<" "<<ls(i)<<" "<<rs(i)<<" "
<<t[i].g[0]<<" "<<t[i].g[1]<<endl;
cerr<<endl;
}
} lct;
#undef fa
void dfs(int u,int fa) {
for(int v : e[u]) if( v != fa )
dfs(v,u), lct.t[v].fa = u, lct.add(u,v);
lct.t[u].g[1] += a[u], lct.up(u);
}
signed main() {
io>>n>>m; For(i,1,n) io>>a[i];
Rep(i,1,n, x,y) io>>x>>y, e[x].pb(y), e[y].pb(x);
dfs(1,0);
while( m-- ) {
int u,x; io>>u>>x; u ^= ans;
lct.access(u), lct.t[u].g[1] += x-a[u], lct.up(u), a[u] = x;
lct.splay(1);
io<<(ans=max(lct.t[1].f[0][0],lct.t[1].f[0][1]))<<endl;
// lct.debug();
}
return 0;
}
插头 DP
LG5056 【模板】插头 DP
四连通网格图，哈密顿回路计数
char readc() { char c; while((c=getchar())!='*'&&c!='.'); return c; }
const int N = 1e6+3;
int n,m,endx,endy,tot[2],st[2][N];
LL ans,f[2][N];
bool cur,a[15][15];
struct HT {
int head[N],nxt[N];
void clear() { tot[cur] = 0, memset(head,0,sizeof head); }
void insert(int x,LL val) {
int y = x % N;
for(int i = head[y]; i; i = nxt[i])
if( st[cur][i] == x ) return f[cur][i] += val, void();
nxt[++tot[cur]] = head[y], head[y] = tot[cur];
st[cur][tot[cur]] = x, f[cur][tot[cur]] = val;
}
} h;
#define get(s,i) ((s>>(i)*2)&3)
#define set(x,i) (x<<(i)*2)
signed main() {
read(n,m);
For(i,1,n) For(j,1,m) if( readc() == '.' ) a[i][j] = 1, endx = i, endy = j;
f[cur][tot[cur]=1] = 1;
For(i,1,n) {
For(j,1,tot[cur]) st[cur][j] <<= 2;
For(j,1,m) {
cur ^= 1, h.clear();
For(k,1,tot[!cur]) {
int s = st[!cur][k], r = get(s,j-1), d = get(s,j);
LL dp = f[!cur][k];
if( !a[i][j] ) {
if( !r && !d ) h.insert(s,dp);
} else if( !r && !d ) {
if( a[i][j+1] && a[i+1][j] )
h.insert(s+set(1,j-1)+set(2,j),dp);
} else if( r && !d ) {
if( a[i][j+1] ) h.insert(s-set(r,j-1)+set(r,j),dp);
if( a[i+1][j] ) h.insert(s,dp);
} else if( !r && d ) {
if( a[i+1][j] ) h.insert(s-set(d,j)+set(d,j-1),dp);
if( a[i][j+1] ) h.insert(s,dp);
} else if( r == 1 && d == 1 ) {
For(p,j+1,m, cnt = 1) {
if( get(s,p) == 1 ) ++cnt;
else if( get(s,p) == 2 && !--cnt ) {
h.insert(s-set(1,j-1)-set(1,j)-set(1,p),dp);
break;
}
}
} else if( r == 2 && d == 2 ) {
rFor(p,j-2,0, cnt = 1) {
if( get(s,p) == 2 ) ++cnt;
else if( get(s,p) == 1 && !--cnt ) {
h.insert(s-set(2,j-1)-set(2,j)+set(1,p),dp);
break;
}
}
} else if( r == 2 && d == 1 ) h.insert(s-set(2,j-1)-set(1,j),dp);
else if( i == endx && j == endy ) ans += dp;
}
}
}
write(ans);
return ocl();
}
其他
- 模拟退火
// NOIP2021 方差
const int N = 1e4+5;
int n,m,a[N];
bool wh[N];
LL ans=LLONG_MAX;
Vi b;
auto sq = [](auto x) { return x * x; };
LL cal() {
static int tmp[N];
LL ave = 0, res = 0;
For(i,2,n) tmp[i] = tmp[i-1] + b[i-2];
For(i,1,n) ave += tmp[i]; ave /= n;
For(i,1,n) res += sq(tmp[i]-ave);
return res / n;
}
void MAIN() {
cin>>n; For(i,1,n) cin>>a[i], a[i] *= n;
Rep(i,1,n) a[i] = a[i+1]-a[i]; sort(a+1,a+n);
m = count(a+1,a+n,a[1]);
while( (double)clock()/CLOCKS_PER_SEC < 0.98 ) {
b.clear();
Rep(i,1,n) wh[i] = rnd(0,1);
rFor(i,n-1,1) if( wh[i] ) b.pb(a[i]);
Rep(i,1,n) if( !wh[i] ) b.pb(a[i]);
LL now = cal(); ckmin(ans,now);
for(double T = 1e6; T > 1e-3; T *= 0.97) {
int l = 0; while( b[l] != a[1] ) ++l;
int p = rnd(0,n-1-m-1);
auto c = b;
if( p < l )
b.erase(b.begin()+p),
b.emplace(lower_bound(b.begin()+l+m-1,b.end(),c[p]),c[p]);
else
p += m,
b.erase(b.begin()+p),
b.emplace(lower_bound(b.begin(),b.begin()+l,c[p],greater<>()),c[p]);
// Rep(i,0,n-1) if( b[i] == a[1] ) {
// Rep(j,0,i) assert(b[j]>=b[j+1]);
// Rep(j,i+1,n-1) assert(b[j-1]<=b[j]);
// break;
// }
LL res = cal();
if( res < now || exp((now-res)/T)*UINT_MAX > mt() ) ckmin(ans, now=res);
else swap(b,c);
}
}
cout<<ans;
}
- 关
assert
// 第一行
#ifndef FS
#define NDEBUG
#endif
- 高精度类
不压位，\(O(n^2)\) 乘法
struct bint : Vi {
bint() { resize(1); }
bint(int x) { clear(); for(; x; x/=10) emplace_back(x%10); }
void clr() { while( size() > 1 && !back() ) pop_back(); }
friend istream& operator >> (istream &io,bint &a) {
string s; io>>s, reverse(all(s));
if( s.back() == '-' ) s.pop_back();
a.resize(sz(s)); Rep(i,0,sz(s)) a[i] = s[i]-'0';
return io;
}
friend ostream& operator << (ostream &io,const bint &a)
{ rFor(i,sz(a)-1,0) cout<<a[i]; return io; }
friend bool operator < (const bint &a,const bint &b) {
if( sz(a) != sz(b) ) return sz(a) < sz(b);
rFor(i,sz(a)-1,0) if( a[i] != b[i] ) return a[i] < b[i];
return 0;
}
friend bint operator + (const bint &a,const bint &b) {
bint c = a; c.resize(max(sz(a),sz(b))+1);
Rep(i,0,sz(b)) c[i] += b[i];
Rep(i,0,sz(c)) if( c[i] >= 10 ) ++c[i+1], c[i] -= 10;
return c.clr(), c;
}
friend bint operator * (const bint &a,const bint &b) {
bint c; c.resize(sz(a)+sz(b)+1);
Rep(i,0,sz(a)) Rep(j,0,sz(b)) c[i+j] += a[i] * b[j];
Rep(i,0,sz(c)) if( c[i] >= 10 ) c[i+1] += c[i]/10, c[i] %= 10;
return c.clr(), c;
}
friend bint operator - (bint a,bint b) {
b.resize(sz(a));
Rep(i,0,sz(a)) {
if( a[i] < b[i] ) --a[i+1], a[i] += 10;
a[i] -= b[i];
}
return a.clr(), a;
}
};
压位，乘法
-
分数类
-
取模类
mint(int x) 要求 x < 2*mod
const int mod = 998244353;
struct mint {
int x; mint(int x=0):x(x<0?x+mod:x<mod?x:x-mod){}
mint(LL y) { y%=mod, x=y<0?y+mod:y; }
mint& operator += (const mint &b) { x=x+b.x<mod?x+b.x:x+b.x-mod; return *this; }
mint& operator -= (const mint &b) { x=x<b.x?x-b.x+mod:x-b.x; return *this; }
mint& operator *= (const mint &b) { x=1ll*x*b.x%mod; return *this; }
friend mint operator + (mint a,const mint &b) { return a+=b; }
friend mint operator - (mint a,const mint &b) { return a-=b; }
friend mint operator * (mint a,const mint &b) { return a*=b; }
}; mint Pow(mint a,LL b=mod-2) { mint c(1);for(;b;b>>=1,a*=a)if(b&1)c*=a;return a; }
- Barrett reduction
【条件】
struct {
LL p,m;
void init(int mod) { p = mod, m = (1ull<<63)/p; }
LL operator () (LL x) {
LL res = x-(__int128(x)*m>>63)*p;
return res<p ? res : res-p;
}
} mod;
- 快读快写
#define getchar() getchar_unlocked()
struct IO {
IO& operator >> (char &x) { while(isspace(x=getchar())); return *this; }
IO& operator >> (char *s) {
while(isspace(*s=getchar())); while(isgraph(*++s=getchar()));
return *s=0, *this;
}
template<typename T>IO& operator >> (T &x) {
x=0;bool f=0;char c;while(!isdigit(c=getchar()))f|=c=='-';
do x=x*10+c-48;while(isdigit(c=getchar()));if(f)x=-x;
return *this;
}
} io;
- linux 对拍
shell
clear; g++ g.cpp -og -DFS -O2
let i=0; while true; do
let i++; printf "#$i\n"
./g; ./a; ./a0
if ! diff out ans -bB; then break; fi
done
- windows 对拍
cpp
for(int i = 1; ; ++i) {
system("ag.exe"), system("a0.exe");
double s = clock(); system("a.exe"); double t = clock();
if( system("fc a.ans a.out") ) puts("WA"), exit(0);
printf("#%d: %.0lfms\n",i,t-s);
}
- 交互
所有输入都要读
endl 换行
浙公网安备 33010602011771号