題解 Dove 打撲克
阿新 • • 發佈:2021-08-11
考場上覺得複雜度是假的就沒怎麼優化,然後考完題解幫我證明了它是真的……
首先合併可以用並查集維護,可以順便維護出集合的大小
對於操作2,發現如果 \(size_i\) 是確定的,可以用權值線段樹很方便的維護出合法的 \(size_j\)的個數
每次只需枚舉出現過的 \(size_i\) 即可,所以我覺得複雜度是假的
- 如果存在 \(\sum a_i = n\) ,那麼有 \(diff \{a_i\} \leqslant \sqrt n\)
我們有 \(\sum size_i = n\) ,所以不同的size個數只有不超過根號個
所以用個unordered_set維護當前存在的size,線段樹查詢即可
yysy,我把線段樹換成樹狀陣列從1700ms變成了400ms
Code:
#include <bits/stdc++.h> using namespace std; #define INF 0x3f3f3f3f #define N 100010 #define ll long long #define reg register int //#define int long long char buf[1<<21], *p1=buf, *p2=buf; #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf, 1, 1<<21, stdin)), p1==p2?EOF:*p1++) inline int read() { int ans=0, f=1; char c=getchar(); while (!isdigit(c)) {if (c=='-') f=-f; c=getchar();} while (isdigit(c)) {ans=(ans<<3)+(ans<<1)+(c^48); c=getchar();} return ans*f; } int n, m; int fa[N], cnt[N]; bool vis[N]; inline int find(int p) {return fa[p]==p?p:fa[p]=find(fa[p]);} namespace force{ void solve() { for (int i=1; i<=n; ++i) fa[i]=i, cnt[i]=1, vis[i]=1; ll ans; for (int i=1,x,y,c,f1,f2; i<=m; ++i) { if (read()&1) { x=read(); y=read(); f1=find(x), f2=find(y); if (f1!=f2) { cnt[f1]+=cnt[f2]; vis[f2]=0; fa[f2]=f1; } } else { ans=0; c=read(); for (int i=1; i<=n; ++i) if (vis[i]) for (int j=i+1; j<=n; ++j) if (vis[j]) if (abs(cnt[i]-cnt[j])>=c) ++ans; printf("%lld\n", ans); } } exit(0); } } namespace task1{ int tl[N<<2], tr[N<<2], sum[N<<2]; #define tl(p) tl[p] #define tr(p) tr[p] #define sum(p) sum[p] #define pushup(p) sum(p)=sum(p<<1)+sum(p<<1|1) void build(int p, int l, int r) { tl(p)=l; tr(p)=r; if (l==r) return ; int mid=(l+r)>>1; build(p<<1, l, mid); build(p<<1|1, mid+1, r); } void upd(int p, int pos, int dat) { if (tl(p)==tr(p)) {sum(p)+=dat; return ;} int mid=(tl(p)+tr(p))>>1; if (pos<=mid) upd(p<<1, pos, dat); else upd(p<<1|1, pos, dat); pushup(p); } int query(int p, int l, int r) { if (l<=tl(p) && r>=tr(p)) return sum(p); int mid=(tl(p)+tr(p))>>1, ans=0; if (l<=mid) ans+=query(p<<1, l, r); if (r>mid) ans+=query(p<<1|1, l, r); return ans; } void solve() { build(1, 1, n); upd(1, 1, n); for (int i=1; i<=n; ++i) fa[i]=i, cnt[i]=1, vis[i]=1; ll ans; for (int i=1,x,y,c,f1,f2; i<=m; ++i) { if (read()&1) { x=read(); y=read(); f1=find(x), f2=find(y); if (f1!=f2) { upd(1, cnt[f1], -1); upd(1, cnt[f2], -1); cnt[f1]+=cnt[f2]; upd(1, cnt[f1], 1); vis[f2]=0; fa[f2]=f1; } } else { ans=0; c=read(); for (reg i=1,l,r; i<=n; ++i) if (vis[i]) { if ((l=cnt[i]-c)>=1) ans+=query(1, 1, l)-(c==0); if ((r=cnt[i]+c+(c==0))<=n) ans+=query(1, r, n); } printf("%lld\n", ans/2); } } exit(0); } } namespace task2{ int tl[N<<2], tr[N<<2], sum[N<<2], tot[N], maxn=1; #define tl(p) tl[p] #define tr(p) tr[p] #define sum(p) sum[p] #define pushup(p) sum(p)=sum(p<<1)+sum(p<<1|1) void build(int p, int l, int r) { tl(p)=l; tr(p)=r; if (l==r) return ; int mid=(l+r)>>1; build(p<<1, l, mid); build(p<<1|1, mid+1, r); } void upd(int p, int pos, int dat) { if (tl(p)==tr(p)) {sum(p)+=dat; return ;} int mid=(tl(p)+tr(p))>>1; if (pos<=mid) upd(p<<1, pos, dat); else upd(p<<1|1, pos, dat); pushup(p); } int query(int p, int l, int r) { if (l<=tl(p) && r>=tr(p)) return sum(p); int mid=(tl(p)+tr(p))>>1, ans=0; if (l<=mid) ans+=query(p<<1, l, r); if (r>mid) ans+=query(p<<1|1, l, r); return ans; } void solve() { build(1, 1, n); upd(1, 1, n); tot[1]=n; for (int i=1; i<=n; ++i) fa[i]=i, cnt[i]=1, vis[i]=1; ll ans; for (int i=1,x,y,c,f1,f2; i<=m; ++i) { if (read()&1) { x=read(); y=read(); f1=find(x), f2=find(y); if (f1!=f2) { upd(1, cnt[f1], -1); upd(1, cnt[f2], -1); --tot[cnt[f1]]; --tot[cnt[f2]]; cnt[f1]+=cnt[f2]; ++tot[cnt[f1]]; maxn=max(maxn, cnt[f1]); upd(1, cnt[f1], 1); vis[f2]=0; fa[f2]=f1; } } else { ans=0; c=read(); for (reg i=1,l,r; i<=maxn; ++i) if (tot[i]) { if ((l=i-c)>=1) ans+=1ll*tot[i]*(query(1, 1, l)-(c==0)); //cout<<"l: "<<l<<' '<<tot[i]*(query(1, 1, l)-(c==0))<<endl; if ((r=i+c+(c==0))<=n) ans+=1ll*tot[i]*query(1, r, n); //cout<<"r: "<<r<<' '<<query(1, r, n)<<endl; } printf("%lld\n", ans/2); } } exit(0); } } namespace task{ unordered_set<int> s; unordered_set<int>::iterator sta[N]; int sum[N], tot[N], top; inline void upd(int i, int dat) {for (; i<=n; i+=i&-i) sum[i]+=dat;} inline int query(int i) {int ans=0; for (; i; i-=i&-i) ans+=sum[i]; return ans;} void solve() { upd(1, n); tot[1]=n; s.insert(1); for (int i=1; i<=n; ++i) fa[i]=i, cnt[i]=1, vis[i]=1; ll ans; for (int i=1,x,y,c,f1,f2; i<=m; ++i) { if (read()&1) { x=read(); y=read(); f1=find(x), f2=find(y); if (cnt[f1]<cnt[f2]) swap(f1, f2); if (f1!=f2) { upd(cnt[f1], -1); upd(cnt[f2], -1); --tot[cnt[f1]]; --tot[cnt[f2]]; cnt[f1]+=cnt[f2]; if (++tot[cnt[f1]]==1) s.insert(cnt[f1]); upd(cnt[f1], 1); vis[f2]=0; fa[f2]=f1; } } else { ans=0; c=read(); int l, r; for (unordered_set<int>::iterator it=s.begin(); it!=s.end(); ++it) { //cout<<"*it: "<<*it<<endl; if (!tot[*it]) {sta[++top]=it; continue;} if ((l=*it-c)>=1) ans+=1ll*tot[*it]*(query(l)-(c==0)); //cout<<"l: "<<l<<' '<<tot[i]*(query(1, 1, l)-(c==0))<<endl; if ((r=*it+c+(c==0))<=n) ans+=1ll*tot[*it]*(query(n)-query(r-1)); //cout<<"r: "<<r<<' '<<query(1, r, n)<<endl; } while (top) s.erase(sta[top--]); printf("%lld\n", ans/2); } } exit(0); } } signed main() { n=read(); m=read(); //if (n<=100) force::solve(); //else if (n<=1000) task1::solve(); //else task2::solve(); task::solve(); return 0; }