学生管理系统 宏 出错 名字查找很诡异 scanf() getchar() 用法

今天做了一个C语言简单的学生管理系统，发现一个很奇怪的现象，学疏才浅，小问题都解决不了，先记录下来吧，后面再解决 再更新。

错误：1，当使用了#denfine N 256 的时候就会出现很多的错误；2，用名字查找的时候出现错误；3，还不是很清楚scanf 和 getchar 这两个函数的相关机制；代码：#include <stdio.h>#include <stdlib.h>#define S 256;char ch;int i=0;struct students{long Number;char Name[256];int Chinese;int Math;int English;char Info[256];}stu[256];int main(int argc, char *argv[]){void READ(void);void SAVE(void);void search_number(int i,int number);void search_name(int i,char *name);void Seeall(int count);void show(int k);int num;READ();printf("STUDENT MANAGMENT INFORMATION SYSTEM\n");printf("1：Add the student's information\n");printf("2：Search the student's information\n");printf("3：Delete the student's information\n");printf("4: Look all of the information\n");printf("5：exit\n");printf("\n");printf("Please enter the number you want to choice(1，2，3,4 or 5):");scanf("%d",&num);while(num!=1&&num!=2&&num!=3&&num!=4&&num!=5){printf("ERROR！Please enter your number again…：");scanf("%d",&num);}do{switch(num){case 1:{printf("\nEnter tht information of the student %dth ！\n",i+1);printf("Enter the number:");scanf("%ld",&stu[i].Number);getchar();printf("Enter the name:");scanf("%s",&stu[i].Name);getchar();printf("Enter the Chinese score:");scanf("%d",&stu[i].Chinese);getchar();printf("Enter the math score:");scanf("%d",&stu[i].Math);getchar();printf("Enter the English score:");scanf("%d",&stu[i].English);getchar();printf("Please enter the other informations:");scanf("%s",stu[i].Info);SAVE();i++;}break;case 2:{do{int str_search;printf("Please enter your choice,1:Number;2:Name:");scanf("%d",&str_search);if(str_search==1){int temp_number;printf("Please enter the number:");scanf("%d",&temp_number);getchar();search_number(i,temp_number);}else if(str_search==2){char *temp_name;temp_name=(char *)malloc(256);printf("Please enter the name:");scanf("%s",temp_name);search_name(i,temp_name);free(temp_name);}printf("ENTER to continue,others to MENUE");ch=getchar();}while(ch=='\n');}break;case 3:{do{int k;int Del_number;char *del;del=(char *)malloc(256);printf("\nPlease enter the number and the name of the student you want to delete:");scanf("%d %s",&Del_number,del);getchar();search_number(i,Del_number);printf("Are you sure to delete the student?1:YES 2:NO");scanf("%d",&k);if(k==1){int m;int j;for(m=0;m<i;m++){if(Del_number==stu[m].Number) break;}for(j=m;j<i;j++){stu[m]=stu[m+1];}i--;printf("SUCCEED!\n");}printf("\nENTER to continue,others to CHOISE");ch=getchar();}while(ch=='\n');}break;case 4:{Seeall(i);}break;case 5:{SAVE();exit(0);}break;default:break;}ch=getchar();printf("\nPlease enter your choice,1,2,3,4 or 5:");scanf("%d",&num);getchar();}while(ch=='\n');SAVE();return 0;}void SAVE(void){int temp;FILE *fp;fp=fopen("C:\\Student.dat","wb");if(fp==NULL){printf("Data save fail\n");}else{fwrite(&i,sizeof(int),1,fp);for(temp=0;temp<i;temp++){fwrite(&stu[temp].Number,sizeof(stu[temp].Number),1,fp);fwrite(&stu[temp].Name,sizeof(stu[temp].Name),1,fp);fwrite(&stu[temp].Chinese,sizeof(stu[temp].Chinese),1,fp);fwrite(&stu[temp].Math,sizeof(stu[temp].Math),1,fp);fwrite(&stu[temp].English,sizeof(stu[temp].English),1,fp);fwrite(&stu[temp].Info,sizeof(stu[temp].Info),1,fp);}}fclose(fp);}void READ(void){int temp;FILE *fp;fp=fopen("C:\\Student.dat","rb");if(fp==NULL){printf("Open fail\n");}else{fread(&i,sizeof(int),1,fp);for(temp=0;temp<i;temp++){fread(&stu[temp].Number,sizeof(stu[temp].Number),1,fp);fread(&stu[temp].Name,sizeof(stu[temp].Name),1,fp);fread(&stu[temp].Chinese,sizeof(stu[temp].Chinese),1,fp);fread(&stu[temp].Math,sizeof(stu[temp].Math),1,fp);fread(&stu[temp].English,sizeof(stu[temp].English),1,fp);fread(&stu[temp].Info,sizeof(stu[temp].Info),1,fp);}}fclose(fp);}void search_number(int i,int number){int k;int flag=0;for(k=0;k<i;k++){if(number==stu[k].Number){show(k);flag=1;}}if(flag==0) printf("Do not fine the student you want");}void search_name(int i,char *name){int flag=0;int k;for(k=0;k<i;k++){if(strcmp(stu[k].Name,name)==0);{show(k);flag=1;}}if(flag==0) printf("Do not fine the student you want");}void Seeall(int count){int k;for(k=0;k<count;k++){show(k);}}void show(int k){printf("\nSUCEED\n");printf("Number:%d Name:%s\n",stu[k].Number,stu[k].Name);printf("Chinese:%d Math%d English%d\n",stu[k].Chinese,stu[k].Math,stu[k].English);printf("Infomation:%s\n",stu[k].Info);printf("\n");}