#include<iostream> using namespace std; int main() { int n; int pre = -1, sum = 0, current; cin >> n; for (int i = 0; i < n; ++i) { cin >> current; if (current != pre) { pre = current;//交错序列没要求连续，实质去重 sum++; } } cout << sum << endl; return 0; }
若求连续交错序列，代码如下：
#include<iostream> using namespace std; int main() { int n; cin >> n; int pre = -1; int current, sum=0,max=0; for (int i = 0; i < n; i++) { cin >> current; if (current != pre) { pre=current; sum++; } else { sum = 1; } if (sum>max) { max=sum; } } cout << max << endl; return 0; }运行结果：
8 1 1 0 0 1 1 0 0 2