题解 | 分段函数

#include <iostream>
#include <iomanip>

using namespace std;

void function(const double &m){
    if(m >= 0 && m < 2) cout << "y=" << 2.5 - m << "\n";
    else if(m >= 2 && m < 4) cout << "y=" << 2 - 1.5 * (m - 3) * (m - 3) << "\n";
    else if(m >= 4 && m < 6) cout << "y=" << m / 2 - 1.5 << "\n";
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    double m;
    cout << fixed << setprecision(1);
    while(cin >> m){
        function(m);
    }
    return 0;
}