C++ 代码
#include<bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int a[N],Left[N],pos[2<<20];
//Left:ai左侧最近匹配数(值为ai^x)的位置
//pos[val]:值为val最近出现的位置
struct Node
{
int l, r;
int max;//区间[l,r]中Left[i]的最大值
}tr[4*N];
//因为ai在右侧即pos[ai]<=r,所以只需max>=l则存在异或对
void pushup(int u)
{
tr[u].max = max(tr[u << 1].max, tr[u << 1 | 1].max);
}
void build(int u, int l, int r)
{
if (l == r)
{
tr[u] = { l,r,Left[l] };
return;
}
else
{
tr[u] = { l,r };
int mid = l + r >> 1;
build(u << 1, l, mid); build(u << 1 | 1, mid + 1, r);
pushup(u);
}
}
int query(int u, int l, int r)
{
if (l <= tr[u].l && tr[u].r <= r)return tr[u].max;
else
{
int mid = tr[u].l + tr[u].r >> 1;
int res = 0;
if (l <= mid)res = max(res, query(u << 1, l, r));
if (r >= mid+1)res = max(res, query(u << 1|1, l, r));
return res;
}
}
int main()
{
int n, m, x; cin >> n >> m >> x;
for (int i = 1; i <= n; i++)
{
scanf("%d", &a[i]);
Left[i] = pos[a[i] ^ x];
pos[a[i]] = i;
}
build(1, 1, n);
int l, r;
while (m--)
{
scanf("%d%d", &l, &r);
if (query(1, l, r) >= l)puts("yes");
else puts("no");
}
}