排序基础：冒泡排序 与 选择排序

#include <iostream>
using namespace std;
int main() {
    int a[] = {64,34,25,12,22,11,90};
    int n = 7;
    for(int i=0; i<n-1; i++){
        bool sw = false;
        for(int j=0; j<n-1-i; j++)
            if(a[j]>a[j+1]){
                int t=a[j]; a[j]=a[j+1]; a[j+1]=t;
                sw=true;
            }
        cout<<"Round "<<i+1<<": ";
        for(int k=0;k<n;k++) cout<<a[k]<<" ";
        cout<<endl;
        if(!sw) break;
    }
    return 0;
}

#include <iostream>
using namespace std;
int main() {
    int n; cin >> n;
    int a[1005];
    for(int i=0;i<n;i++) cin>>a[i];
    for(int i=0;i<n-1;i++){
        int minIdx = i;
        for(int j=i+1;j<n;j++)
            if(a[j]<a[minIdx]) minIdx=j;
        cout<<"Round "<<i+1<<": min="<<a[minIdx]<<" at pos "<<minIdx<<endl;
        if(minIdx!=i){
            int t=a[i]; a[i]=a[minIdx]; a[minIdx]=t;
        }
    }
    for(int i=0;i<n;i++) cout<<a[i]<<" ";
    cout<<endl;
    return 0;
}

#include <iostream>
using namespace std;
void bubble(int a[],int n,int&cmp,int&swp){
    cmp=swp=0;
    for(int i=0;i<n-1;i++){
        bool sw=false;
        for(int j=0;j<n-1-i;j++){
            cmp++;
            if(a[j]>a[j+1]){
                int t=a[j];a[j]=a[j+1];a[j+1]=t;
                swp++; sw=true;
            }
        }
        if(!sw) break;
    }
}
void selection(int a[],int n,int&cmp,int&swp){
    cmp=swp=0;
    for(int i=0;i<n-1;i++){
        int mi=i;
        for(int j=i+1;j<n;j++){
            cmp++;
            if(a[j]<a[mi]) mi=j;
        }
        if(mi!=i){
            int t=a[i];a[i]=a[mi];a[mi]=t;
            swp++;
        }
    }
}
int main(){
    int a[]={5,3,8,1,2}, b[]={5,3,8,1,2};
    int n=5, bc,bs,sc,ss;
    bubble(a,n,bc,bs);
    selection(b,n,sc,ss);
    cout<<"Bubble: cmp="<<bc<<" swp="<<bs<<endl;
    cout<<"Selection: cmp="<<sc<<" swp="<<ss<<endl;
    return 0;
}

#include <iostream>
using namespace std;
void cocktailSort(int a[], int n) {
    int left = 0, right = n - 1;
    while (left < right) {
        // 正向：最大值冒到右边
        bool sw = false;
        for (int j = left; j < right; j++)
            if (a[j] > a[j+1]) {
                int t=a[j]; a[j]=a[j+1]; a[j+1]=t;
                sw = true;
            }
        right--;
        if (!sw) break;
        // 反向：最小值冒到左边
        sw = false;
        for (int j = right; j > left; j--)
            if (a[j] < a[j-1]) {
                int t=a[j]; a[j]=a[j-1]; a[j-1]=t;
                sw = true;
            }
        left++;
        if (!sw) break;
    }
}
int main() {
    int a[] = {5,1,4,2,8,0,3};
    cocktailSort(a, 7);
    for(int i=0;i<7;i++) cout << a[i] << " ";
    cout << endl;
    return 0;
}

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
struct Student {
    string name;
    int score;
};
// 自定义比较：成绩降序，成绩相同按姓名升序
bool cmp(Student a, Student b) {
    if (a.score != b.score)
        return a.score > b.score;  // 成绩高在前
    return a.name < b.name;        // 姓名字典序
}
int main() {
    int n; cin >> n;
    Student s[1005];
    for(int i=0;i<n;i++)
        cin >> s[i].name >> s[i].score;
    stable_sort(s, s+n, cmp);  // 稳定排序！
    for(int i=0;i<n;i++)
        cout << s[i].name << " " << s[i].score << endl;
    return 0;
}