牛客15534 Dragon Ball Super

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题解

查询区间颜色个数，这不是莫队裸题吗

代码

#include 
#include 
#include 
#define iinf 0x3f3f3f3f
#define linf (1ll<<60)
#define eps 1e-8
#define maxn 1000010
#define maxe 1000010
#define cl(x) memset(x,0,sizeof(x))
#define rep(i,a,b) for(i=a;i<=b;i++)
#define drep(i,a,b) for(i=a;i>=b;i--)
#define em(x) emplace(x)
#define emb(x) emplace_back(x)
#define emf(x) emplace_front(x)
#define fi first
#define se second
#define de(x) cerr<<#x<<" = "<
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll read(ll x=0)
{
    ll c, f(1);
    for(c=getchar();!isdigit(c);c=getchar())if(c=='-')f=-f;
    for(;isdigit(c);c=getchar())x=x*10+c-0x30;
    return f*x;
}
struct UnionFind
{
	ll f[maxn], size[maxn];
	void init(ll n)
	{
		for(auto i=1;i<=n;i++)f[i]=i, size[i]=1;
	}
	ll find(ll x){return f[x]==x?x:f[x]=find(f[x]);}
	void merge(ll x, ll y)
    {
        auto fx=find(x), fy=find(y);
        f[fx]=fy;
        if(fx!=fy)size[fy]+=size[fx];
    }
}uf;
ll cnt[maxn], now, id[maxn], l[maxn], r[maxn], col[maxn], ans[maxn];
void upd(ll x, ll d)
{
    if(d==1)
    {
        now += (cnt[col[x]]==0);
    }
    else
    {
        now -= (cnt[col[x]]==1);
    }
    cnt[col[x]] += d;
}
int main()
{
    ll T=read();
    while(T--)
    {
        ll n=read(), m=read(), i;
        uf.init(n);
        rep(i,1,m)
        {
            ll a=read(), b=read();
            uf.merge(a,b);
        }
        rep(i,1,n)col[i]=uf.find(i);
        ll q=read();
        rep(i,1,q)
        {
            l[i]=read(), r[i]=read(), id[i]=i;
        }
        ll S = 320;
        sort(id+1,id+q+1,[&](ll a, ll b){return l[a]/S==l[b]/S ? r[a]<r[b] : l[a]/S<l[b]/S; });
        now=0;
        rep(i,1,n)cnt[i]=0;
        ll L=1, R=0;
        rep(i,1,q)
        {
            for(;L>l[id[i]];L--)upd(L-1,+1);
            for(;R<r[id[i]];R++)upd(R+1,+1);
            for(;L<l[id[i]];L++)upd(L,-1);
            for(;R>r[id[i]];R--)upd(R,-1);
            ans[id[i]]=now;
        }
        rep(i,1,q)printf("%lld\n",ans[i]);
    }
    return 0;
}