题解 | #分段函数#

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

double f(int x) {
    double y;
    if (x >= 0 && x < 2) {
        y = -x + 2.5;
    } else if (x >= 2 && x < 4) {
        y = 2 - 1.5 * (x - 3) * (x - 3);
    } else if (x >= 4 && x < 6) {
        y = x / 2.0 - 1.5;
    }
    return y;
}

int main() {
    int m, x;
    cin >> m;
    while (m--) {
        cin >> x;
        printf("y=%.1f\n", f(x));
    }
    return 0;
}