Given two1dvectors, implement an iterator to return their elements alternately.

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Yes

Example

Given two 1d vectors:

v1 = [1, 2]
v2 = [3, 4, 5, 6]

By calling next repeatedly until hasNext returnsfalse, the order of elements returned by next should be:[1, 3, 2, 4, 5, 6].

line 8 not bool isV1 , 
line 16 missing ++ , should not return here
line 20 missing negation

class ZigzagIterator {
public:
    /**
     * @param v1 v2 two 1d vectors
     */
    ZigzagIterator(vector<int>& v1, vector<int>& v2) {
        // initialize your data structure here.
        isV1 = !v1.empty();
        begin[0] = v1.begin(), end[0] = v1.end();
        begin[1] = v2.begin(), end[1] = v2.end();
    }

    int next() {
        // Write your code here
        int res = 0;
        if (isV1) {
           res = *begin[0]++;
        } else {
           res = *begin[1]++;
        }
        isV1 = !isV1;
        return res;
    }

    bool hasNext() {
        // Write your code here
        if (begin[0] == end[0]) {
            isV1 = false;
        }
        if (begin[1] == end[1]) {
            isV1 = true;
        }

        return begin[0] != end[0] || begin[1] != end[1];
    }

private:
    vector<int>::iterator begin[2], end[2];
    bool isV1;
};

/**
 * Your ZigzagIterator object will be instantiated and called as such:
 * ZigzagIterator solution(v1, v2);
 * while (solution.hasNext()) result.push_back(solution.next());
 * Ouptut result
 */