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;
}