P16072: Intersecció de taules

#include <iostream>
#include <vector>
using namespace std;

typedef vector<double> Row;

Row interseccio(const Row&v1, const Row&v2) {
    int s1 = v1.size();
    int s2 = v2.size();
    int s3;
    if (s1 > s2) s3 = s2;
    else s3 = s1;
    Row aux(s3);
    int i, j, k;
    i = j = k = 0;
    while (i < s1 and j < s2) {
        if (v1[i] > v2[j]) ++j;
        else if (v1[i] < v2[j]) ++i;
        else if (k == 0 or aux[k-1] != v1[i]) {
            aux[k] = v1[i];
            ++i;
            ++j;
            ++k;
        }
        else {
            ++i;
            ++j;
        }
    }
    Row v3(k);
    for (i = 0; i < k; ++i) v3[i] = aux[i];
    return v3;
}

int main() {
    int n;
    cin >> n;
    Row v1(n);
    for (int i = 0; i < n; ++i) cin >> v1[i];
    int k;
    cin >> k;
    Row v2(k);
    for (int i = 0; i < k; ++i) cin >> v2[i];
    Row v3;
    v3 = interseccio(v1, v2);
    for (int i = 0; i < v3.size(); ++i) {
        if (i > 0) cout << ' ';
        cout << v3[i];
    }
    cout << endl;
}