开数组的时候少开了一个一个位置，wa很难过。
#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<vector>
#include<queue>
#define ls 2*rt
#define rs 2*rt+1
#define lson ls,L,mid
#define rson rs,mid+1,R
#define ll long long
using namespace std;
typedef pair<int,int> pii;
const ll inf = 0x3f3f3f3f;
/*void dis(int a[], int n){printf("总数为%d个\n",n); for(int i = 0; i < n; i++) cout<<a[i]<<", ";cout<<endl<<"------------------"<<endl;
}*/const int mx = 1e5+1;
int f[2000000];
int a[mx],po[mx];
int n,m,k;
ll ans[mx],sum;
struct no{int l,r,id;
}q[mx];
bool cmp(no &a, no &b){if(po[a.l] != po[b.l])return po[a.l] < po[b.l];elsereturn a.r < b.r;
}
void add(int x){sum += f[a[x]^k];f[a[x]]++;
}
void dele(int x){f[a[x]]--;sum -= f[a[x]^k];
}
int main(){//int T=10;int l,r;scanf("%d%d%d",&n,&m,&k);a[0] = 0;int sq = sqrt(n);memset(f,0,sizeof(f));f[0] = 1;sum = 0;for(int i = 1; i <= n; i++){scanf("%d",a+i);a[i] = a[i]^a[i-1];po[i] = i/sq;}for(int i = 1; i <= m; i++){scanf("%d%d",&q[i].l,&q[i].r);q[i].id = i;}sort(q+1,q+m+1,cmp);l = 1; r = 0; for(int i = 1;i <= m; i++){while(q[i].l < l)l--,add(l-1);while(q[i].l > l)dele(l-1),l++;while(q[i].r < r)dele(r),r--;while(q[i].r > r)r++,add(r); ans[q[i].id] = sum;}for(int i = 1; i <= m; i++)printf("%I64d\n",ans[i]);return 0;
}