题意:
给定一个数组,要求两种操作:求区间和;让区间的每个数异或上x
思路:
每一位开一棵线段树,节点维护(某一位上的)1的数量。
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 100010, M = 25;
int n, m, w[N];
struct node {
int l, r; int sum; bool tag; //是否取反
} tr[M][N*4];
void pushup(int t, int u)
{
tr[t][u].sum = tr[t][u<<1].sum + tr[t][u<<1|1].sum;
}
void pushdown(int t, int u)
{
node &root = tr[t][u], &left = tr[t][u<<1], &right = tr[t][u<<1|1];
if(root.tag)
{
left.tag ^= 1, right.tag ^= 1;
left.sum = left.r-left.l+1 - left.sum;
right.sum = right.r-right.l+1 - right.sum;
root.tag = 0;
}
}
void build(int t, int u, int l, int r)
{
if(l == r) tr[t][u] = {l, r, (w[l]>>t)&1};
else
{
tr[t][u] = {l, r};
int mid = l + r >> 1;
build(t, u<<1, l, mid), build(t, u<<1|1, mid+1, r);
pushup(t, u);
}
}
void modify(int t, int u, int l, int r)
{
if(tr[t][u].l >= l && tr[t][u].r <= r)
{
tr[t][u].tag ^= 1;
tr[t][u].sum = tr[t][u].r-tr[t][u].l+1 - tr[t][u].sum;
}
else
{
pushdown(t, u);
int mid = tr[t][u].l + tr[t][u].r >> 1;
if(l <= mid) modify(t, u<<1, l, r);
if(r > mid) modify(t, u<<1|1, l, r);
pushup(t, u);
}
}
int query(int t, int u, int l, int r)
{
if(tr[t][u].l >= l && tr[t][u].r <= r) return tr[t][u].sum;
pushdown(t, u);
int mid = tr[t][u].l + tr[t][u].r >> 1, sum = 0;
if(l <= mid) sum += query(t, u<<1, l, r);
if(r > mid) sum += query(t, u<<1|1, l, r);
return sum;
}
signed main()
{
scanf("%d", &n);
for(int i = 1; i <= n; i++) scanf("%d", &w[i]);
for(int i = 0; i < M; i++) build(i, 1, 1, n);
scanf("%d", &m); while(m--) {
int op, l, r, x; scanf("%d%d%d", &op, &l, &r);
if(op == 1) {
long long res = 0;
for(int i = 0; i < M; i++) res += query(i, 1, l, r) * (1ll<<i);
printf("%lld\n", res);
}
else {
scanf("%d", &x);
for(int i = 0; i < M; i++) if((x>>i)&1) modify(i, 1, l, r);
}
}
return 0;
}