Question

求助一个c语言题目？

这个函数好复杂 哪个大佬能详细讲解一下呢

Answer 1

#include <stdio.h>

#include <malloc.h>

#include <string.h>

#define __TEST_VRSER__

struct SUer{

int sNumber;

char sName[20];

float fMath;

};

typedef SUer DATA;

struct SNode{

DATA data;

SNode *pNext;

};

SNode *g_pHead = NULL;

void AddHead(DATA _data){

SNode *p = (SNode*)malloc(sizeof(SNode));

p->data = _data;

p->pNext = g_pHead;

g_pHead = p;

}

void AddTalie(DATA _data){

SNode *pNew = (SNode*)malloc(sizeof(SNode));

pNew->data = _data;

pNew->pNext = NULL;

if (!g_pHead) {

g_pHead = pNew;

}

SNode *p = g_pHead;

while(p->pNext != NULL)

p = p->pNext;

p->pNext = pNew;

}

void Print(){

SNode *p = g_pHead;

while (p) {

printf("%d\t%s\t%0.2f\n",p->data.sNumber,p->data.sName,p->data.fMath);

#ifdef __TEST_VRSER__

printf("p=0x%p\n",p);

#endif

p = p->pNext;

}

printf("\n");

}

void Modinfy(){

int number;

printf("请输入你要查询的学号:");

scanf("%d",&number);

SNode *p = g_pHead;

while(p->pNext){

if (p->data.sNumber == number) {

break;

}

p = p->pNext;

}

if (!p) {

puts("你输入的学号不存在:");

return;

}

printf("%d\t\%s\t\%0.1f\n\n",p->data.sNumber,p->data.sName,p->data.fMath);

printf("请输入姓名和成绩");

scanf("%s",p->data.sName,sizeof(p->data.sName));

scanf("%f",&p->data.fMath);

Print();

}

void Input(const int &_dt){

int m;

printf("请输入学号: \n");

scanf("%d",&m);

DATA gData;

gData.sNumber = m;

printf("请输入名字: \n");

scanf("%s",gData.sName,sizeof(gData.sName));

printf("请输入成绩: \n");

scanf("%f",&gData.fMath);

if (1 == _dt){

AddHead(gData);

}else if(2 == _dt){

AddTalie(gData);

}

}

int Find(const int &_data){

SNode *p = g_pHead;

int i = 0;

while (p) {

if (p->data.sNumber == _data) {

return i;

}

i++;

p = p->pNext;

}

return -1;

}

int Delete(const int &nNumber){

SNode *p = g_pHead;

SNode *p1 = NULL;

if (!p)

return 0;

if (p->data.sNumber == nNumber) {

g_pHead = p->pNext;

free(p);

return 1;

}

while (p) {

if (p->data.sNumber == nNumber) {

p1->pNext = p->pNext;

free(p);

return 1;

}

p1 = p;

p = p->pNext;

}

return NULL;

}

int Judge(SNode *q,SNode *m,const int &nIndx){

switch (nIndx) {

case 1:

return q->data.sNumber < m->data.sNumber;

case 2:

return strcmp(q->data.sName, m->data.sName) <0;

case 3:

//return q->data.fMath < m->data.fMath ? q->data.fMath : m->data.fMath;

return q->data.fMath < m->data.fMath;

break;

}

return 0;

}

void Sort(const int &Indx){

SNode *p = g_pHead;

if (!g_pHead) {

printf("你当前的数据为空");

return;

}

while (p->pNext) {

SNode *q = p->pNext;

SNode *m = p;

while (q) {

//if (q->data.fMath < m->data.fMath) {

if(Judge(q, m, Indx)){

m = q;

q = q->pNext;

}

}

if (m != p) {

DATA t = p->data;

p->data = m->data;

m->data = t;

}

p = p->pNext;

}

}

void PrintS(SNode *ps[]){

puts("学号\t姓名\t成绩");

int i = 0;

while (ps[i]) {

//SNode *p = ps[i];

//printf("打印外排链表:%d\t%s\t%0.2f\n",p->data.sNumber,

// p->data.sName,p->data.fMath);

printf("打印外排链表:%d\t%s\t%0.2f\n",ps[i]->data.sNumber,

ps[i]->data.sName,ps[i]->data.fMath);

i++;

}

}

//表外排序

void SortWai(const int &Indx){

if (!g_pHead) {

return;

}

SNode *p = g_pHead;

// SNode *ps[100] ={0};

int sum = 0;

int i = 0;

while (p) { //求链表个数

p = p->pNext;

++sum;

}

SNode* *ps = (SNode**)malloc(sizeof(SNode*)*(sum+1));//sum+1 malloc 动态申请数组的时候对申请一个作为空节点判断结束的时候用，也可以在插入的时候添加一个GetSize()函数去记录插入的个数;

sum = 0;

p = g_pHead;

while (p) {

ps[sum] = p;

p = p->pNext;

++sum;

}

ps[sum] = NULL;

while (i < sum - 1) {

int j = i + 1;

int m = i;

while (j < sum) {

if (ps[j]->data.sNumber < ps[m]->data.sNumber) //新手注意这个里的ps[xx]是一个二级指针 也就是SNode -> pa[xxx].xx

m = j;

++j;

}

if (m != i) {

SNode *t = ps[i];

ps[i] = ps[m];

ps[m] = t;

}

++i;

}

// ps[i] = NULL;

PrintS(ps);

free(ps);

}

void PT(){

printf("****************************** \n");

printf("****** c测试 ******* \n");

printf("****************************** \n");

}

int main(int argc, const char * argv[]){

#ifdef __TEST_VRSER__

puts("当前版本是测试版");

#else

PT();

#endif

Input(1);

Input(2);

Input(1);

// Input(2);

Print();

SortWai(1);

return 0;

}

Answer 2

哪个函数不理解？