ALDS1_2_C-Stable Sort(稳定排序)

Stable Sort
Let’s arrange a deck of cards. There are totally 36 cards of 4 suits(S, H, C, D) and 9 values (1, 2, … 9). For example, ‘eight of heart’ is represented by H8 and ‘one of diamonds’ is represented by D1.

Your task is to write a program which sorts a given set of cards in ascending order by their values using the Bubble Sort algorithms and the Selection Sort algorithm respectively. These algorithms should be based on the following pseudocode:

BubbleSort©
1 for i = 0 to C.length-1
2 for j = C.length-1 downto i+1
3 if C[j].value < C[j-1].value
4 swap C[j] and C[j-1]
SelectionSort©
1 for i = 0 to C.length-1
2 mini = i
3 for j = i to C.length-1
4 if C[j].value < C[mini].value
5 mini = j
6 swap C[i] and C[mini]
Note that, indices for array elements are based on 0-origin.

For each algorithm, report the stability of the output for the given input (instance). Here, ‘stability of the output’ means that: cards with the same value appear in the output in the same order as they do in the input (instance).
Input
The first line contains an integer N, the number of cards.

N cards are given in the following line. Each card is represented by two characters. Two consecutive cards are separated by a space character.

Output
In the first line, print the arranged cards provided by the Bubble Sort algorithm. Two consecutive cards should be separated by a space character.

In the second line, print the stability (“Stable” or “Not stable”) of this output.

In the third line, print the arranged cards provided by the Selection Sort algorithm. Two consecutive cards should be separated by a space character.

In the fourth line, print the stability (“Stable” or “Not stable”) of this output.

Constraints
1 ≤ N ≤ 36

Sample Input 1
5
H4 C9 S4 D2 C3
Sample Output 1
D2 C3 H4 S4 C9
Stable
D2 C3 S4 H4 C9
Not stable
Sample Input 2
2
S1 H1
Sample Output 2
S1 H1
Stable
S1 H1
Stable

---

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

struct Card {
    char suit, value;
};
// 冒泡排序法
void bubble(struct Card A[], int n) {
    // 标记是否需要继续冒泡
    int flag = 1;
    for (int i = 0; flag; i++) {
        flag = 0;
        for (int j = n - 1; j >= i + 1; j--) {
            // 交换两个相邻的元素
            if (A[j].value < A[j - 1].value) {
                swap(A[j], A[j - 1]);
                flag = 1;
            }
        }
    }
}
// 选择排序法
void selection(struct Card A[], int n) {
    for (int i = 0; i < n; i++) {
        int minj = i;
        for (int j = i; j < n; j++) {
            if (A[j].value < A[minj].value)
                minj = j;
        }
        if (i != minj)
            swap(A[i], A[minj]);
    }
}
// 冒泡排序法是稳定排序，选择排序后的花色和其比较则可得知排序是否稳定的
bool isStable(struct Card C1[], struct Card C2[], int n) {
    for (int i = 0; i < n; i++) {
        if (C1[i].suit != C2[i].suit)
            return false;
    }
    return true;
}
// 打印输出
void print(struct Card C[], int n) {
    for (int i = 0; i < n; i++) {
        printf("%c%c%c", C[i].suit, C[i].value, i == n - 1 ? '\n' : ' ');
    }
}
int main() {
    Card C1[100], C2[100];
    int n;

    scanf("%d", &n);
    getchar();
    for (int i = 0; i < n; i++) {
        scanf("%c%c", &C1[i].suit, &C1[i].value);
        getchar();
        C2[i] = C1[i];
    }
    // 对于C1数列进行冒泡排序，对C2数列进行选择排序，然后比较两者排序后的花色
    // 则可得知选择排序是否稳定
    bubble(C1, n);
    selection(C2, n);

    print(C1, n);
    printf("Stable\n");
    print(C2, n);
    if (isStable(C1, C2, n))
        printf("Stable\n");
    else
        printf("Not stable\n");

    return 0;
}