jQuery使<select class="form-control" multiple="" id="pns" name="pns"> </select> 这个下拉框恢复默认样式

你可以使用以下代码将该下拉框恢复默认样式：

$("#pns").removeClass("form-control").removeAttr("multiple");

这会移除该下拉框上的 "form-control" 类和 "multiple" 属性，使其恢复默认样式。注意，这会影响该下拉框的样式和功能，因此请谨慎使用。

相关问题

#define _CRT_SECURE_NO_WARNINGS 1 #include <iostream> #include <cstdlib> #include <cstdio> #include <algorithm> using namespace std; struct cake { double num = 0; double sale = 0; double pns = 0; } moon[1010]; bool cmp(cake a, cake b) { return (a.pns - b.pns) > 0; } int main(int argc, char *argv[]) { int n = 0; double s = 0; double total = 0; scanf("%d%lf", &n, &s); for (int i = 1; i <= n; i++) { scanf("%lf", &moon[i].num); } for (int i = 1; i <= n; i++) { scanf("%lf", &moon[i].sale); moon[i].pns = moon[i].sale / moon[i].num; } sort(moon + 1, moon + n + 1, cmp); for (int j = 1; j <= n; j++) { if (s < moon[j].num) { total += s * moon[j].pns; break; } else if (s >= moon[j].num) { total += moon[j].sale; s -= moon[j].num; } } printf("%.2f", total); return 0; }简化代码

以下是简化后的代码：

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

struct cake {
    double num, sale, pns;
} moon[1010];

bool cmp(cake a, cake b) {
    return (a.pns - b.pns) > 0;
}

int main() {
    int n;
    double s, total = 0;
    cin >> n >> s;
    for (int i = 1; i <= n; i++) {
        cin >> moon[i].num;
    }
    for (int i = 1; i <= n; i++) {
        cin >> moon[i].sale;
        moon[i].pns = moon[i].sale / moon[i].num;
    }
    sort(moon + 1, moon + n + 1, cmp);
    for (int j = 1; j <= n; j++) {
        if (s < moon[j].num) {
            total += s * moon[j].pns;
            break;
        } else {
            total += moon[j].sale;
            s -= moon[j].num;
        }
    }
    printf("%.2f", total);
    return 0;
}

#define _CRT_SECURE_NO_WARNINGS 1 #include <iostream> #include <algorithm> using namespace std; struct cake { double num = 0; double sale = 0; double pns = 0; } moon[1010]; bool cmp(cake a, cake b) { return (a.pns - b.pns) > 0; } int main() { int n = 0; double s = 0; double total = 0; scanf("%d%lf", &n, &s); for (int i = 1; i <= n; i++) { scanf("%lf", &moon[i].num); } for (int i = 1; i <= n; i++) { scanf("%lf", &moon[i].sale); moon[i].pns = moon[i].sale / moon[i].num; } sort(moon + 1, moon + n + 1, cmp); for (int j = 1; j <= n; j++) { if (s < moon[j].num) { total += s * moon[j].pns; break; } else if (s >= moon[j].num) { total += moon[j].sale; s -= moon[j].num; } } printf("%.2f", total); return 0; }优化代码

以下是优化后的代码：

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

struct cake {
    double num;
    double sale;
    double pns;
};

bool cmp(const cake& a, const cake& b) {
    return a.pns > b.pns;
}

int main() {
    int n;
    double s;
    double total = 0;
    scanf("%d%lf", &n, &s);
    cake moon[n];
    for (int i = 0; i < n; i++) {
        scanf("%lf", &moon[i].num);
    }
    for (int i = 0; i < n; i++) {
        scanf("%lf", &moon[i].sale);
        moon[i].pns = moon[i].sale / moon[i].num;
    }
    sort(moon, moon + n, cmp);
    for (int j = 0; j < n; j++) {
        if (s < moon[j].num) {
            total += s * moon[j].pns;
            break;
        } else if (s >= moon[j].num) {
            total += moon[j].sale;
            s -= moon[j].num;
        }
    }
    printf("%.2f", total);
    return 0;
}

主要优化点：

1. 结构体成员变量的默认值可以省略
2. 将结构体比较函数改为传参并标记为 const
3. 数组下标从 1 开始改为从 0 开始
4. 将结构体数组定义移动到 main 函数内
5. 简化变量命名
6. 删除无用变量声明

这些优化不仅使代码更加简洁，还可以提高代码的可读性和可维护性。