func1 : AccountData* createData(char* name, int money);

func2 : AccountData* userQuery(AccountData* data);

func1 help bank to store user's data and func2 help bank to return a copy data to user (In order to avoid user directly modify the money information in bank)

The bank give you a simple data struct to implement above two function.

typedef struct _AccountData {

    char* name;

    int money;

} AccountData;

main.c

#include <stdio.h> #include <stdlib.h> #include "function.h" char s[100]; int money, attack_money; AccountData* data; int main(){ // store money in bank scanf("%s",s); scanf("%d",&money); scanf("%d",&attack_money); getchar(); // ignore newline AccountData* data = createData(s, money); // copy data and let user to query (handle process in bank) AccountData* userData = userQuery(data); // evil person try to attack userData->money = attack_money; // the money in bank printf("---money in bank---\nname: %s\nmoney: %d\n",data->name, data->money); if(data->money != userData->money){ printf("warning! the user is try to modify the money in bank to %d\n",userData->money); }else{ printf("query finish\n"); } // free data free(userData->name); free(userData); free(data->name); free(data); return 0; }

function.h

#include <stdio.h> #include <stdlib.h> #include <string.h> typedef struct _AccountData { char* name; int money; } AccountData; AccountData* createData(char* name, int money); AccountData* userQuery(AccountData* data);

note that: you can use strlen(const char* str) in string.h to get the length of string

hint: you should not directly assign name to data->name, you need  to malloc some memory space to copy the name's value.

data->name = name (x)