#include <stdio.h> 
#include <stdlib.h> 
#include <time.h> 
#define MAX 10 
#define SWAP(x,y) {int t; t = x; x = y; y = t;} 

void selectionSort(int[]);  // 選擇排序 
void insertionSort(int[]);   // 插入排序 
void bubbleSort(int[]);  // 氣泡排序 

int main(void) {  
    srand(time(NULL)); 

    printf("排序前：");
    
    int number[MAX] = {0}; 
    int i;
    for(i = 0; i < MAX; i++) { 
        number[i] = rand() % 100; 
        printf("%d ", number[i]); 
    } 

    printf("\n請選擇排序方式：\n"); 
    printf("(1)選擇排序\n(2)插入排序\n(3)氣泡排序\n:"); 
    scanf("%d", &i); 

    switch(i) { 
        case 1: selectionSort(number); break; 
        case 2: insertionSort(number); break; 
        case 3: bubbleSort(number); break; 
        default: printf("選項錯誤(1..3)\n"); 
    } 

    int k;
    for(k = 0; k < MAX; k++) 
        printf("%d ", number[k]); 
    printf("\n");
        
    return 0; 
} 

void selectionSort(int number[]) { 
    int i; 
    for(i = 0; i < MAX-1; i++) { 
        int m = i; 
        int j;
        for(j = i+1; j < MAX; j++) 
            if(number[j] < number[m]) 
                m = j; 

        if(i != m) 
            SWAP(number[i], number[m]) 
    } 
 } 

 void insertionSort(int number[]) { 
    int j;
    for(j = 1; j < MAX; j++) { 
        int tmp = number[j]; 
        int i = j - 1; 
        while(tmp < number[i]) { 
            number[i+1] = number[i]; 
            i--; 
            if(i == -1) 
                break; 
        } 
        number[i+1] = tmp; 
    } 
} 

void bubbleSort(int number[]) { 
    int flag = 1;
    int i; 
    for(i = 0; i < MAX-1 && flag == 1; i++) { 
        flag = 0; 
        int j;
        for(j = 0; j < MAX-i-1; j++) { 
            if(number[j+1] < number[j]) { 
                SWAP(number[j+1], number[j]); 
                flag = 1; 
            } 
        } 
    } 
} 

循序搜尋法（使用衛兵）

#include <stdio.h> 
#include <stdlib.h> 
#include <time.h> 
#define MAX 10 
#define SWAP(x,y) {int t; t = x; x = y; y = t;} 

int search(int[]); 
int partition(int[], int, int); 
void quickSort(int[], int, int); 

int main(void) { 
    srand(time(NULL)); 
    
    int number[MAX+1] = {0};    

    int i;
    for(i = 1; i <= MAX; i++) 
        number[i] = rand() % 100; 

    quickSort(number, 1, MAX); 

    printf("數列："); 
    for(i = 1; i <= MAX; i++) 
        printf("%d ", number[i]); 
    
    printf("\n輸入搜尋值："); 
    scanf("%d", &number[0]); 

    int find = search(number);
    if(find >= 0) 
        printf("\n找到數值於索引 %d ", find); 
    else 
        printf("\n找不到數值"); 

    printf("\n"); 

    return 0; 
} 

int search(int number[]) { 
    int i = MAX; 
    while(number[i] != number[0]) i--; 
    return i; 
} 

int partition(int number[], int left, int right) { 
    int s = number[right]; 
    int i = left - 1; 

    int j;
    for(j = left; j < right; j++) { 
        if(number[j] <= s) { 
            i++; 
            SWAP(number[i], number[j]); 
        } 
    } 

    SWAP(number[i+1], number[right]); 
    return i+1; 
} 

void quickSort(int number[], int left, int right) { 
    if(left < right) { 
        int q = partition(number, left, right); 
        quickSort(number, left, q-1); 
        quickSort(number, q+1, right); 
    } 
}