滴滴校招2018 XOR

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main() {
int n;
while (cin >> n) {
vector<int> a;
for (int i = 0; i < n; i++) {
int tmp;
cin >> tmp;
a.push_back(tmp);
}
vector<bool> flag(n, false);
vector<int> res(n, 0);
int count = 0;
for (int i = 0; i < n; i++) {
int x_xor = a[i];
if (a[i] == 0) {
flag[i] = true;
count++;
continue;
}
for (int j = i - 1; j > 0; j--) {
if (flag[j] == false) {
x_xor ^= a[j];
}
else break;
if (x_xor == 0) {
flag[i] = true;
count++;
}
}
}
cout << count << endl;
}
return 0;
}