洛谷P3759 [TJOI2017]不勤劳的图书管理员【树状数组套主席树】

题目链接

题解

树状数组套主席树板题

#include<algorithm>

#include<iostream>

#include<cstring>

#include<cstdio>

#include<cmath>

#include<map>

#define Redge(u) for (int k = h[u],to; k; k = ed[k].nxt)

#define REP(i,n) for (int i = 1; i <= (n); i++)

#define mp(a,b) make_pair<int,int>(a,b)

#define cls(s) memset(s,0,sizeof(s))

#define cp pair<int,int>

#define LL long long int

#define lbt(x) (x & -x)

using namespace std;

const int maxn = 100005,maxm = 10000005,INF = 1000000000,P = 1000000007;

inline int read(){

	int out = 0,flag = 1; char c = getchar();

	while (c < 48 || c > 57){if (c == '-') flag = -1; c = getchar();}

	while (c >= 48 && c <= 57){out = (out << 3) + (out << 1) + c - 48; c = getchar();}

	return out * flag;

}

int sum[maxm],siz[maxm],ls[maxm],rs[maxm],cnt;

void upd(int u){

	sum[u] = (sum[ls[u]] + sum[rs[u]]) % P;

	siz[u] = siz[ls[u]] + siz[rs[u]];

}

void Modify(int& u,int l,int r,int pos,int v,int vv){

	if (!u) u = ++cnt;

	if (l == r){sum[u] += v; siz[u] += vv; return;}

	int mid = l + r >> 1;

	if (mid >= pos) Modify(ls[u],l,mid,pos,v,vv);

	else Modify(rs[u],mid + 1,r,pos,v,vv);

	upd(u);

}

cp Query(int u,int l,int r,int L,int R){

	if (!u) return mp(0,0);

	if (l >= L && r <= R) return mp(sum[u],siz[u]);

	int mid = l + r >> 1;

	if (mid >= R) return Query(ls[u],l,mid,L,R);

	if (mid < L) return Query(rs[u],mid + 1,r,L,R);

	cp t = Query(ls[u],l,mid,L,R),tt = Query(rs[u],mid + 1,r,L,R);

	return mp((t.first + tt.first) % P,t.second + tt.second);

}

int rt[maxn << 2],n,m,N = 100005,A[maxn],V[maxn]; LL ans;

void modify(int u,int pos,int v,int vv){

	for (int i = u; i <= N; i += lbt(i))

		Modify(rt[i],1,N,pos,v,vv);

}

cp query(int l,int r,int L,int R){

	if (L > R) return mp(0,0);

	cp re = mp(0,0),t;

	for (int i = r; i; i -= lbt(i)){

		t = Query(rt[i],1,N,L,R);

		re.first = (re.first + t.first) % P;

		re.second += t.second;

	}

	for (int i = l - 1; i; i -= lbt(i)){

		t = Query(rt[i],1,N,L,R);

		re.first = (re.first - t.first + P) % P;

		re.second -= t.second;

	}

	return re;

}

int main(){

	n = read(); m = read();

	int x,y; cp t,tt;

	REP(i,n){

		A[i] = read(); V[i] = read();

		if (i - 1){

			t = query(1,i - 1,A[i] + 1,N);

			ans = ((ans + t.first) % P + 1ll * t.second * V[i] % P) % P;

		}

		modify(i,A[i],V[i],1);

	}

	while (m--){

		x = read(); y = read();

		if (x == y){printf("%lld\n",(ans % P + P) % P); continue;}

		if (x > y) swap(x,y);

		if (A[x] < A[y]) ans = ((ans + V[x]) % P + V[y]) % P;

		else ans = ((ans - (V[x] + V[y]) % P) % P + P) % P;

		if (x < y){

			t = query(x + 1,y - 1,A[x] + 1,N);

			tt = query(x + 1,y - 1,1,A[x] - 1);

			t.first = (t.first - tt.first) % P; t.second -= tt.second;

			ans = ((ans + t.first) % P + 1ll * V[x] * t.second % P) % P;

			t = query(x + 1,y - 1,1,A[y] - 1);

			tt = query(x + 1,y - 1,A[y] + 1,N);

			t.first = ((t.first - tt.first) % P + P) % P; t.second -= tt.second;

			ans = ((ans + t.first) % P + 1ll * V[y] * t.second % P) % P;

		}

		modify(x,A[x],-V[x],-1);

		modify(y,A[y],-V[y],-1);

		modify(x,A[y],V[y],1);

		modify(y,A[x],V[x],1);

		swap(A[x],A[y]); swap(V[x],V[y]);

		printf("%lld\n",(ans % P + P) % P);

	}

	return 0;

}

巴特西

洛谷P3759 [TJOI2017]不勤劳的图书管理员【树状数组套主席树】

题目链接

题解

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巴特西

洛谷P3759 [TJOI2017]不勤劳的图书管理员 【树状数组套主席树】

题目链接

题解

最新文章

热门文章

洛谷P3759 [TJOI2017]不勤劳的图书管理员【树状数组套主席树】