数组的基本操作

#include <iostream>
#include <stdlib.h>
using namespace std;
struct SqList {
    int *elem;
    int length;
};

int InitList(SqList &L,int num)
{
    L.elem = new int[num];
    if (!L.elem) {
        cout << "Creation failed!" << endl; 
        exit(1);
    }
    L.length = num;
    cout << "Created successfully." << endl;
    cout << "Please enter the elements." << endl;
    for (int i = 0; i < num;i++) {
        cin >> L.elem[i];
        if (i==num-1)
            cout << "Input complete."<<endl;
    }
    return 0;
}

void DestroyList(SqList &L)
{
    if (L.elem) {
        delete L.elem;
        cout << "Destruction succeeded." << endl;
    }
    else
        cout << "Destroy failed." << endl;
}

void ClearList(SqList &L)
{
    if (L.elem) {
        L.length = 0;
        cout << "Clear success." << endl;
    }
    else
        cout << "Purge failed." << endl;
}

int ListEmpty(SqList &L)
{
    if (L.elem) {
        if (!L.length)
            return 1;    
    }
    return 0;
}

int ListLength(SqList &L)
{
    if (L.elem) {
        cout << L.length << endl;
    }
    else
        cout << "Find failed." << endl;
    return 0;
}

int GetElem(SqList &L,int num,int &e)
{
    if (!L.elem) {
        cout << "Find failed." << endl;
        return 0;
    }
    if (num>=L.length||num<0){
        cout << "Find failed." << endl;
        return 0;
    }
    e = L.elem[num];
    return 1;
}

int LocateElem(SqList &L,int e)
{
    if (!L.elem) {
        cout << "Find failed." << endl;
        return 0;
    }
    int flag = 0;
    for (int i = 0; i < L.length;i++) {
        if (e<L.elem[i]) {
            cout << i << endl;
            flag = 1;
        }
    }
    if (flag==0)
        cout << 0 << endl;
    return 0;
}

int PriorElem(SqList &L,int &cur_e,int &pre_e)
{
    if (!L.elem||cur_e==L.elem[0])
        cout << "Find failed." << endl;
    for (int i = 1; i < L.length;i++) {
        if (cur_e==L.elem[i]) {
            pre_e = L.elem[i - 1];
        }
    }
    return 0;
}

int NextElem(SqList &L,int &cur_e,int &next_e)
{
    if (!L.elem||cur_e==L.elem[L.length-1])
        cout << "Find failed." << endl;
    for (int i = 0; i < L.length-1;i++) {
        if (cur_e==L.elem[i]){
            next_e = L.elem[i + 1];
        }
    }
    return 0;
}

int ListInsert(SqList &L,int num,int e)
{
    if (!L.elem||num<0||num>L.length) {
        cout << "Insert failed." << endl;
        return 0;
    }
    for (int i = L.length - 1; i >= num;i--) {
        L.elem[i + 1] = L.elem[i];
    }
    L.elem[num] = e;
    L.length++;
    cout << "Insert Successfully." << endl;
    return 0;
}

int ListDelete(SqList &L,int num,int &e)
{
    if (!L.elem||num<0||num>=L.length) {
        cout << "Delete failed." << endl;
        return 0;
    }
    e = L.elem[num];
    for (int i = num; i < L.length-1;i++) {
        L.elem[i] = L.elem[i+1];
    }
    L.length--;
    cout << "Delete succeeded." << endl;
    return 0;
}
int ListTraverse(SqList &L)
{
    if (!L.elem) {
        cout << "Traversal failure." << endl;
        return 0;
    }
    for (int i = 0; i < L.length;i++)
        cout << L.elem[i] << " ";
    cout << endl;
    return 0;
}
int main()
{
    int n,num,cnt,pre_e,cur_e,next_e,e;
    SqList sq;
    cout << "Please enter what you want to do." << endl
         << "1:Create a linear table." << endl
         << "2:Destroying a linear table." << endl
         << "3:Empty the linear table." << endl
         << "4:Empty table." << endl
         << "5:To find the length of a linear table." << endl
         << "6:To find the value of the element I of a linear table." << endl
         << "7:Position the first number greater than num." << endl
         << "8:Looking for a precursor." << endl
         << "9:Looking for a successor." << endl
         << "10:Inserting elements." << endl
         << "11:Delete elements." << endl
         << "12:Traversing a linear table." << endl
         << "Input 0 end." << endl;
    while (~scanf("%d",&n)&&n) {
        cnt = 0;
        switch(n) {
            case 1:
                cout << "Please enter the number of elements." << endl;
                cin >> num;
                InitList(sq,num);
                break;
            case 2:
                DestroyList(sq);
                break;
            case 3:
                ClearList(sq);
                break;
            case 4:
                if (ListEmpty(sq))
                    cout << "TRUE" << endl;
                else
                    cout << "FLASE" << endl;
                break;
            case 5:
                ListLength(sq);
                break;
            case 6:
                int num, e;
                cout << "Please enter the ordinal number you want to find." << endl;
                cin >> num;
                if (GetElem(sq, num, e))
                    cout << e << endl;
                break;
            case 7:
                cout << "Please enter the number you want to compare." << endl;
                cin >> num;
                LocateElem(sq,num);
                break;
            case 8:
                pre_e = NULL;
                cout << "Please enter the current element." << endl;
                cin >> cur_e;
                PriorElem(sq, cur_e, pre_e);
                cout << pre_e<<endl;
                break;
            case 9:
                next_e = NULL;
                cout << "Please enter the current element." << endl;
                cin >> cur_e;
                NextElem(sq, cur_e, next_e);
                cout << next_e << endl;
                break;
            case 10:
                cout << "Please enter the number where you want to insert." << endl
                     << "Input num and where." << endl;
                cin >> e >> num;
                ListInsert(sq, num, e);
                break;
            case 11:
                cout << "Please enter number you want to delete." << endl;
                cin >> num;
                ListDelete(sq, num, e);
                cout << e << endl;
                break;
            case 12:
                ListTraverse(sq);
        }
    }
    system("pause");
    return 0;
}