C++：悬赏高，Bubble Sort及指针问题。急在线等啊等。

Question

程序代码如下，要求填写空白代码。
#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

struct StudentInfo {
int stdnumber;
double grade;
};

int main() {

const int arraySize = 30;
StudentInfo stdInfo[arraySize];
StudentInfo* pInfo[arraySize];

srand((unsigned)time(0));

for (int i=0; i<arraySize; ++i) {
pInfo[i] = &stdInfo[i];
}

for (int i=0; i<arraySize; ++i) {
pInfo[i]->grade = rand()%5 + ((double)rand()/(2*RAND_MAX));
pInfo[i]->stdnumber = rand();
}

cout << "Before Sorting: " << endl;
cout << "StudnetNumber" << "\t" << "Grade" << endl;

for (int i=0; i<arraySize; ++i) {
cout << pInfo[i]->stdnumber << "\t\t" << pInfo[i]->grade << endl;
}

????? //此处填代码，不止一行...

cout << "After Sorting: " << endl;
cout << "StudnetNumber" << "\t" << "Grade" << endl;

for (int i=0; i<arraySize; ++i) {
cout << pInfo[i]->stdnumber << "\t\t" << pInfo[i]->grade << endl;
}

return 0;
}

输出如下：

Answer 1

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;


struct StudentInfo {
    int    stdnumber;
    double grade; 
};


int main() {
    
    const int arraySize = 30;
    StudentInfo stdInfo[arraySize];
    StudentInfo* pInfo[arraySize];
    
    srand((unsigned)time(0));
    for (int i=0; i<arraySize; ++i) {
        pInfo[i] = &stdInfo[i];
    }
    
    
    for (int i=0; i<arraySize; ++i) {
        pInfo[i]->grade = rand()%5 + ((double)rand()/(2*RAND_MAX));
        pInfo[i]->stdnumber = rand();
    }
    
    cout << "Before Sorting: " << endl;
    cout << "StudnetNumber" << "\t" << "Grade" << endl;
    
    for (int i=0; i<arraySize; ++i) {
        cout << pInfo[i]->stdnumber <<  "\t\t" << pInfo[i]->grade << endl;
        
    }
    
    
    //此处填代码，不止一行...   
        for(int k=0; k < arraySize; k++) {
        for(int m =arraySize-1; m>k;m--) {
            if (pInfo[m]->grade>pInfo[m-1]->grade){
                StudentInfo tmp;
                tmp.grade = pInfo[m-1]->grade;
                tmp.stdnumber = pInfo[m-1]->stdnumber;
                pInfo[m-1]->grade=pInfo[m]->grade;
                pInfo[m-1]->stdnumber=pInfo[m]->stdnumber;
                pInfo[m]->grade=tmp.grade;
                pInfo[m]->stdnumber=tmp.stdnumber;
            }
        }
    }
    
    
    
    cout << "After Sorting: " << endl;
    cout << "StudnetNumber" << "\t" << "Grade" << endl;
    
    for (int i=0; i<arraySize; ++i) {
        cout << pInfo[i]->stdnumber <<  "\t\t" << pInfo[i]->grade << endl;
    }
    
    return 0;
    
}

追问

有错呀 大哥你能运行一下吗？需填空白处的第二行 那不应该是i吧
for(int m =arraySize-1; m>i;m-- {

追答

嘻嘻，抢回答抢的太急，后面更新过了～

//此处填代码，不止一行...           for(int k=0; k < arraySize; k++) {
        for(int m =arraySize-1; m>k;m--) {
            if (pInfo[m]->grade>pInfo[m-1]->grade){
                StudentInfo tmp;
                tmp.grade = pInfo[m-1]->grade;
                tmp.stdnumber = pInfo[m-1]->stdnumber;
                pInfo[m-1]->grade=pInfo[m]->grade;
                pInfo[m-1]->stdnumber=pInfo[m]->stdnumber;
                pInfo[m]->grade=tmp.grade;
                pInfo[m]->stdnumber=tmp.stdnumber;
            }
        }
    }

Answer 2

填的思路是，比较指针指向的值的大小，如果小，就把指针指向挪个位置，懒得写了