文章目錄

• 題目
• 程式碼

題目

已知線性表La和Lb中的資料元素按值非遞減(非遞減就是遞增)有序排列，
現要求將La和Lb歸併為一個新的線性表Lc，且Lc中的資料元素仍按值非
遞減有序排列。
示例輸入：La = {3, 5, 8, 11};
		 Lb = {2, 6, 8, 9, 11, 15, 20};
示例輸出: Lc = {2, 3, 5, 6, 8, 8, 9, 11, 11, 15, 20};

程式碼

/**
 * @author: Simon_z
    已知線性表La和Lb中的資料元素按值非遞減(非遞減就是遞增)有序排列，現要求將La和Lb歸併為
    一個新的線性表Lc，且Lc中的資料元素仍按值非遞減有序排列。
    示例輸入：La = {3, 5, 8, 11};
              Lb = {2, 6, 8, 9, 11, 15, 20};
    示例輸出: Lc = {2, 3, 5, 6, 8, 8, 9, 11, 11, 15, 20};
 */
 

//  使用動態陣列分配La，Lb記憶體，需輸入La, Lb的length

#include <stdio.h>
#include <stdlib.h>
#include <iostream>
using namespace std;

int *CreateDynamicArray(int *p, int arrayLength);
int Compare(int La_array[], int Lb_array[], int La_value, int Lb_value);

int main(int argv,char *argc[]){
    int *
 
La, *Lb;
    int La_Length, Lb_Length, Lc_Length;
    bool Perform;
    //構造陣列La，Lb, Lc
    printf("Please input La_Length: ");
    scanf("%d", &La_Length);
    printf("Please input La_array: ");
    La = CreateDynamicArray(La, La_Length);
    printf("Please input Lb_Length: ");
    scanf("%d", &
 
Lb_Length);
    printf("Please input Lb_array: ");
    Lb = CreateDynamicArray(Lb, Lb_Length);
    //構造陣列Lc不需要手動輸入資料，所以直接在main方法裡構造即可，不需要呼叫
    //*CreateDynamicArray方法
    Lc_Length = La_Length + Lb_Length; //由於不需要去重所以Lc的長度即是La_Length + Lb_Length
    int Lc[Lc_Length] = {0};
    printf("初始化Lc\n");
    for(int i = 0; i < Lc_Length; i++){
        printf("%d ", Lc[i]);
    }
    if(!Lc){
        printf("Array creation failed!\n");
    }
    //輸出插入前的La，Lb
    printf("Brfore Merge: \n");
    printf("La: ");
    for (int i = 0; i < La_Length; i++){
        printf("%d ", La[i]);
    }
    printf("\n");
    printf("Lb: ");
    for (int i = 0; i < Lb_Length; i++){
        printf("%d ", Lb[i]);
    }
    //執行歸併演算法
    printf("\n");
    printf("After Merge: \n");

    int La_Location = 0, Lb_Location = 0, Lc_Location = 0;  //給La, Lb, Lc新增位置指標
    while((La_Location <= La_Length) && (Lb_Location <= Lb_Length)){
        printf("La_Location:%d La_Length:%d Lb_Location:%d Lb_Length:%d\n", La_Location, La_Length, Lb_Location, Lb_Length);
        //判斷Compare方法的返回值,返回true插入Lb的元素,返回false插入La的元素
        Perform = Compare(La, Lb, La_Location, Lb_Location);

        for(int i = 0; i < Lc_Length; i++){
            printf("%d ", Lc[i]);
        }
        printf("\n");
        if (Perform == true){
            Lc[Lc_Location] = Lb[Lb_Location];
            /*指標下移*/
            Lc_Location += 1;
            Lb_Location += 1;
        }else if (Perform == false){
            Lc[Lc_Location] = La[La_Location];
            /*指標下移*/
            Lc_Location += 1;
            La_Location += 1;
        }
    }
    /*將剩餘不用比較的資料插入Lc*/
    printf("La_Location:%d La_Length:%d", La_Location, La_Length);
    if (La_Location > La_Length){
        int i,j;
        /*由於while裡主動將Lc指標下移, 所以Lc_Location - 1*/
        for (i = Lb_Location, j = Lc_Location - 1; j < Lc_Length; i++, j++){
            Lc[j] = Lb[i];
        }

    }else{
        int i,j;
        /*由於while裡主動將Lc指標下移, 所以Lc_Location - 1*/
        for (i = La_Location, j = Lc_Location - 1; j < Lc_Length; i++, j++){
            Lc[j] = La[i];
        }
    }

    //輸出插入後的Lc
    printf("\nLc: ");
    for (int i = 0; i < Lc_Length; i++){
        printf("%d ", Lc[i]);
    }

    /*釋放記憶體*/
    free(La);
    free(Lb);
    free(Lc);
    return 0;
}

//返回頭指標即可
int *CreateDynamicArray(int *p, int arrayLength){
    int c;
    p = (int *)malloc(arrayLength*sizeof(int)); //在堆中開闢陣列記憶體
    for(int i = 0;i < arrayLength; i++)
    {
        scanf("%d", &c);
        p[i] = c;
    }
    return p;
}

//比較La和Lb的對應元素決定插入哪個陣列的元素
int Compare(int La_array[], int Lb_array[], int La_value, int Lb_value){
    bool Judge = true;
    if (La_array[La_value] > Lb_array[Lb_value]){
        Judge = true;
    }else{
        Judge = false;
    }
    return Judge;
}