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  • codeforces 242E

    E. XOR on Segment
    time limit per test
    4 seconds
    memory limit per test
    256 megabytes
    input
    standard input
    output
    standard output

    You've got an array a, consisting of n integers a1, a2, ..., an. You are allowed to perform two operations on this array:

    1. Calculate the sum of current array elements on the segment [l, r], that is, count value al + al + 1 + ... + ar.
    2. Apply the xor operation with a given number x to each array element on the segment [l, r], that is, execute . This operation changes exactly r - l + 1 array elements.

    Expression  means applying bitwise xor operation to numbers x and y. The given operation exists in all modern programming languages, for example in language C++ and Java it is marked as "^", in Pascal — as "xor".

    You've got a list of m operations of the indicated type. Your task is to perform all given operations, for each sum query you should print the result you get.

    Input

    The first line contains integer n (1 ≤ n ≤ 105) — the size of the array. The second line contains space-separated integers a1, a2, ..., an(0 ≤ ai ≤ 106) — the original array.

    The third line contains integer m (1 ≤ m ≤ 5·104) — the number of operations with the array. The i-th of the following m lines first contains an integer ti (1 ≤ ti ≤ 2) — the type of the i-th query. If ti = 1, then this is the query of the sum, if ti = 2, then this is the query to change array elements. If the i-th operation is of type 1, then next follow two integers li, ri (1 ≤ li ≤ ri ≤ n). If the i-th operation is of type 2, then next follow three integers li, ri, xi (1 ≤ li ≤ ri ≤ n, 1 ≤ xi ≤ 106). The numbers on the lines are separated by single spaces.

    Output

    For each query of type 1 print in a single line the sum of numbers on the given segment. Print the answers to the queries in the order in which the queries go in the input.

    Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use the cin, cout streams, or the %I64dspecifier.

    Examples
    input
    Copy
    5
    4 10 3 13 7
    8
    1 2 4
    2 1 3 3
    1 2 4
    1 3 3
    2 2 5 5
    1 1 5
    2 1 2 10
    1 2 3
    output
    Copy
    26
    22
    0
    34
    11
    input
    Copy
    6
    4 7 4 0 7 3
    5
    2 2 3 8
    1 1 5
    2 3 5 1
    2 4 5 6
    1 2 3
    output
    Copy
    38
    28

    题意;

    两个操作:

    1.输出区间l,r的和

    2.让区间l,r每个数异或x

    思路:

    把数拆成二进制,对每一位建一棵线段树,记录每个数这一位是否为1,然后求一段区间的和就是这些线段树上这一段区间1的个数乘上2的位数-1次方,异或一个数x的话,我们将x拆成二进制,如果x的某一位为1的话那么就是对这段区间所有数的这一位都要变化,这一位线段树上直接区间异或标记就好了。

    实现代码:

    #include<bits/stdc++.h>
    using namespace std;
    #define lson l,m,rt<<1
    #define rson m+1,r,rt<<1|1
    #define mid int m = (l + r) >> 1
    #define ll long long
    const int M = 1e5 + 10;
    
    int sum[M<<2][30],lazy[M<<2][30],a[M],bit[30];
    
    void pushup(int rt){
        for(int i = 1;i <= 21;i ++)
        sum[rt][i] = sum[rt<<1][i] + sum[rt<<1|1][i];
    }
    
    void pushdown(int l,int r,int rt){
        for(int i = 1;i <= 21;i ++)
        if(lazy[rt][i]){
            mid;
            sum[rt<<1][i] = m-l+1-sum[rt<<1][i];
            sum[rt<<1|1][i] = r-m-sum[rt<<1|1][i];
            lazy[rt<<1][i] ^= lazy[rt][i];
            lazy[rt<<1|1][i] ^= lazy[rt][i];
            lazy[rt][i] = 0;
        }
    }
    
    void build(int l,int r,int rt){
        if(l == r){
            int x = a[l],cnt = 1;
            while(x){
                sum[rt][cnt++] = x%2;
                x = x/2;
            }
            return;
        }
        mid;
        build(lson); build(rson);
        pushup(rt);
    }
    
    void update(int L,int R,int x,int l,int r,int rt){
        if(L <= l&&R >= r){
            for(int i = 1;i <= 21;i ++){
                if(x&(1<<(i-1))){
                    sum[rt][i] = r-l+1-sum[rt][i];
                    lazy[rt][i] ^= 1;
                }
            }
            return ;
        }
        pushdown(l,r,rt);
        mid;
        if(L <= m) update(L,R,x,lson);
        if(R > m) update(L,R,x,rson);
        pushup(rt);
    }
    
    ll query(int L,int R,int l,int r,int rt){
        if(L <= l&&R >= r){
            ll cnt = 0;
            for(int i = 1;i <= 21;i ++){
                cnt += 1LL*sum[rt][i]*bit[i];
            }
            return cnt;
        }
        pushdown(l,r,rt);
        mid; ll ret = 0;
        if(L <= m) ret += query(L,R,lson);
        if(R > m) ret += query(L,R,rson);
        return ret;
    }
    
    int main(){
        int n,q,l,r,x,op;
        bit[1] = 1;
        for(int i = 2;i <= 21;i ++)
            bit[i] = bit[i-1]*2;
        while(scanf("%d",&n)!=EOF){
            for(int i = 1;i <= n;i ++)
                scanf("%d",&a[i]);
            build(1,n,1);
            scanf("%d",&q);
            while(q--){
                scanf("%d",&op);
                if(op == 1){
                    scanf("%d%d",&l,&r);
                    printf("%lld
    ",query(l,r,1,n,1));
                }
                else{
                    scanf("%d%d%d",&l,&r,&x);
                    update(l,r,x,1,n,1);
                }
            }
        }
        return 0;
    }
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  • 原文地址:https://www.cnblogs.com/kls123/p/9912153.html
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