Luogu3919 【模板】可持久化数组（主席树）

主席树模板题，注意空间\((n+m) \log(n)\)
#include <iostream>

#include <cstdio>

#include <cstring>

#include <algorithm>

#include <cmath>

#define R(a,b,c) for(register int  a = (b); a <= (c); ++ a)

#define nR(a,b,c) for(register int  a = (b); a >= (c); -- a)

#define Max(a,b) ((a) > (b) ? (a) : (b))

#define Min(a,b) ((a) < (b) ? (a) : (b))

#define Fill(a,b) memset(a, b, sizeof(a))

#define Abs(a) ((a) < 0 ? -(a) : (a))

#define Swap(a,b) a^=b^=a^=b

#define ll long long

//#define ON_DEBUG

#ifdef ON_DEBUG

#define D_e_Line printf("\n\n----------\n\n")

#define D_e(x)  cout << #x << " = " << x << endl

#define Pause() system("pause")

#define FileOpen() freopen("in.txt","r",stdin);

#else

#define D_e_Line ;

#define D_e(x)  ;

#define Pause() ;

#define FileOpen() ;

#endif

struct ios{

    template<typename ATP>ios& operator >> (ATP &x){

        x = 0; int f = 1; char c;

        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-')  f = -1;

        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();

        x*= f;

        return *this;

    }

}io;

using namespace std;

const int N = 20000007;

struct Chairman{

    // space complexity : (n + m) * log(n)

    int rt[1000007], T[N], L[N], R[N];

    int treeIndex;

    inline int Build(int l, int r){

    	int root = ++treeIndex;

    	if(l == r){

    		io >> T[root];

    		return root;

    	}

    	int mid = (l + r) >> 1;

    	L[root] = Build(l, mid);

    	R[root] = Build(mid + 1, r);

    	return root;

    }

    inline int Updata(int rt, int l, int r, int x, int w){

    	int root = ++treeIndex;

    	if(l == r){

    		T[root] = w;

    		return root;

    	}

    	L[root] = L[rt], R[root] = R[rt];

    	int mid = (l + r) >> 1;

    	if(x <= mid) L[root] = Updata(L[rt], l, mid, x ,w);

    	else R[root] = Updata(R[rt], mid + 1, r, x, w);

    	return root;

    }

    inline int Query(int rt, int l, int r, int x){

    	if(l == r) return T[rt];

    	int mid = (l + r) >> 1;

    	if(x <= mid) return Query(L[rt], l, mid, x);

    	else return Query(R[rt], mid + 1, r, x);

    }

}t;

int main(){

    t.treeIndex=0;

    int n,m;

    io >> n >> m;

    t.Build(1,n);

    t.rt[0]=1;

    R(i,1,m){

    	int edition,opt;

        io >> edition >> opt;

        if(opt==1){

        	int pos, newValue;

            io >> pos >> newValue;

            t.rt[i] = t.Updata(t.rt[edition], 1, n, pos, newValue);

        }

        if(opt==2){

        	int pos;

        	io >> pos;

            printf("%d\n", t.Query(t.rt[edition], 1, n, pos));

            t.rt[i] = t.rt[edition];

        }

    }

    return 0;

}
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Luogu3919 【模板】可持久化数组（主席树）

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