realloc() 예제

가상 계좌 프로그램

001: #include <stdio.h>
002: #include <conio.h>
003: #include <stdlib.h>
004: 
005: const int NAME_LEN=20;
006: int customer_count=0;
007: struct Account
008: {
009:         int id; //계좌번호
010:         int balance; //잔액
011:         char name[NAME_LEN];  //고객이름
012: };
013: void PrintMenu(); //메뉴출력
014: void MakeAccount(); //계좌개설
015: void Deposit(); //입금
016: void WithDraw(); //출금
017: void Remainder(); //잔액조회
018: 
019: Account *acc=(Account *)malloc(1*sizeof(Account)); //초기 메모리 할당
020: void main (){
021:         int selectedmenu=0;
022:         
023:         PrintMenu();
024:         scanf("%d",&selectedmenu);
025: 
026:         switch(selectedmenu){
027:         case 1:
028:                 MakeAccount();
029:                 break;
030:         case 2:
031:                 Deposit();
032:                 break;
033:         case 3:
034:                 WithDraw();
035:                 break;
036:         case 4:
037:                 Remainder();
038:                 break;
039:         case 5:
040:                 exit(0);
041:         }
042: }
043: void PrintMenu(){ //메뉴출력
044:         system("cls");
045:         printf("----------------------------\n");
046:         printf("1. 계좌 개설\n");
047:         printf("2. 입금\n");
048:         printf("3. 출금\n");
049:         printf("4. 전체 고객 잔액조회\n");
050:         printf("5. 종료\n");
051:         printf("----------------------------\n");
052:         printf("Select Menu : ");
053: }
054: void MakeAccount(){ //계좌개설
055:         system("cls");
056:         acc=(Account *)realloc(acc, (customer_count+1)*sizeof(Account));
057:         printf("\n이름을 입력하세요 : ");
058:         scanf("%s",&acc[customer_count].name);
059: 
060:         printf("\n계좌 번호를 입력하세요 : ");
061:         scanf("%d",&acc[customer_count].id);
062: 
063:         printf("\n입금 금액을 입력하세요 : ");
064:         scanf("%d",&acc[customer_count].balance);
065: 
066:         customer_count++;
067:         main();
068: }
069: void Remainder(){ //계좌개설
070:         system("cls");
071:         printf("------------------------------------------\n");
072:         printf("            전체 고객 잔액조회            \n");
073:         printf("------------------------------------------\n");
074:         printf("    이름    |       ID      |       잔액  \n");
075:         printf("------------------------------------------\n");
076:         for(int i=0;i<customer_count;i++)
077:                 printf("%12s %12d %14d \n",acc[i].name,acc[i].id,acc[i].balance);
078:         getch();
079:         main();
080: }
081: void Deposit(){ //입금
082:         int temp, k, money;
083:         system("cls");
084:         printf("고객님의 ID를 입력하여 주셔요 : ");
085:         scanf("%d",&temp);
086:         for(k=0;k<customer_count;k++){
087:                 if(temp==acc[k].id){
088:                         printf("------------------------------------------\n");
089:                         printf("           고객님의 정보 입니다.          \n");
090:                         printf("------------------------------------------\n");
091:                         printf("    이름    |       ID      |       잔액  \n");
092:                         printf("------------------------------------------\n");
093:                         printf("%12s %12d %14d \n",acc[k].name,acc[k].id,acc[k].balance);
094:                         break;
095:                 }
096:         }
097:         printf("입금액을 입력해 주셔요 : ");
098:         scanf("%d",&money);
099:         acc[k].balance+=money;
100: 
101:         printf("\n------------------------------------------\n");
102:         printf("           입금 후  정보 입니다.          \n");
103:         printf("------------------------------------------\n");
104:         printf("    이름    |       ID      |       잔액  \n");
105:         printf("------------------------------------------\n");
106:         printf("%12s %12d %14d \n",acc[k].name,acc[k].id,acc[k].balance);
107:         getch();
108:         main();
109: }
110: void WithDraw(){ //출금
111:         int temp, k, money;
112:         system("cls");
113:         printf("고객님의 ID를 입력하여 주셔요 : ");
114:         scanf("%d",&temp);
115:         for(k=0;k<customer_count;k++){
116:                 if(temp==acc[k].id){
117:                         printf("------------------------------------------\n");
118:                         printf("           고객님의 정보 입니다.          \n");
119:                         printf("------------------------------------------\n");
120:                         printf("    이름    |       ID      |       잔액  \n");
121:                         printf("------------------------------------------\n");
122:                         printf("%12s %12d %14d \n",acc[k].name,acc[k].id,acc[k].balance);
123:                         break;
124:                 }
125:         }
126:         printf("출금액을 입력해 주셔요 : ");
127:         scanf("%d",&money);
128:         acc[k].balance-=money;
129: 
130:         printf("\n------------------------------------------\n");
131:         printf("           처리 후  정보 입니다.          \n");
132:         printf("------------------------------------------\n");
133:         printf("    이름    |       ID      |       잔액  \n");
134:         printf("------------------------------------------\n");
135:         printf("%12s %12d %14d \n",acc[k].name,acc[k].id,acc[k].balance);
136:         getch();
137:         main();
138: }