P71711: Ziga-Zaga

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


typedef vector<int> Columna;
typedef vector<Columna> Matriu;

bool ZigaZaga(const Matriu& M, int f, int c) {
    int comp = M[0][0];
    bool primer = true;
    for (int j  = 0; j < c; ++j) {
                if (j%2 == 0) { //Baixar
                    for (int i =0; i < f; ++i) {
                        if (not primer) {
                            if (M[i][j] <= comp) return false;
                            else comp = M[i][j];
                        }
                        primer = false;
                    }
                }
                else { //Pujar
                    for (int i = f-1; i >= 0; --i) {
                        if (M[i][j] <= comp) return false;
                        else comp = M[i][j];
                    }
                }
    }
    return true;
}

int main() {
    int f, c;
    int count = 0;
    while (cin >> f >> c) {
        ++count;
        Matriu M(f, Columna(c));
        for (int i = 0; i < f; ++i) {
            for (int j = 0; j < c; ++j) cin >> M[i][j];
        }
        if (ZigaZaga(M, f, c)) cout << "matriu " << count << ": si" << endl;
        else cout << "matriu " << count << ": no" << endl;
    }
}