#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<string.h>
typedef struct{char names[30];
               int age;
               char position[30];
               char sex;} data;
void age(data *emp; int n;);
void sex(data *emp; int n;);
void name(data *emp; int n;);
void pos(data *emp; int n;);
void show(data *emp; int n;);
data *emp=0;
int n=0,i;
char ch;

void input(data *emp);
int main(){


printf("Input employees' information here:\n");
again:
    printf("\nEmployee[%d]:\n",n+1);
    emp=(data*)realloc(emp,(n+1)*sizeof(data));
    if(emp==0) return 0;
printf("%10s:","Name"); scanf("%30[^\n]",(emp+n)->names); fflush(stdin);
printf("%10s:","age"); scanf("%d",&((emp+n)->age)); fflush(stdin);
printf("%10s:","Position"); scanf("%30[^\n]",(emp+n)->position); fflush(stdin);
printf("%10s:","Sex"); scanf("%c",&((emp+n)->sex)); fflush(stdin);
    n++;
printf("\nMore employee? (ESC to stop): ");
if(getch()!=27) goto again;
printf("Here are all of your employees' information:");
for(i=0;i<n;i++){
    printf("\n[%d]",i+1);
    printf("\t%s",emp[i].names);
    printf("\t%d",emp[i].age);
    printf("\t%s",emp[i].position);
    printf("\t%c",emp[i].sex);}
printf("\nWhat do you want data to be sorted by?\n");
printf("1/ names\n2/ age\n3/ position\n4/ sex\n");
printf("\nYour choice: ");
ch=getche();
switch(ch){
    case 1 : name(emp, n); show(emp, n); break;
    case 2 : age(emp, n); show(emp, n); break;
    case 3 : pos(emp, n); show(emp, n); break;
    case 4 : sex(emp, n); show(emp, n); break;}
return 0;
}

void name(data *emp; int n;){
int i,j;
char temp[30];
for(i=0;i<n-1;i++)
    for(j=i+1;j<n;j++)
        if(strcmp(emp[i].names,emp[j].names)>0) {strcpy(temp,emp[i].names);
                                                 strcpy(emp[i].names,emp[j].names);
                                                 strcpy(emp[j].names,temp);}

}

void pos(data *emp; int n;){
int i,j;
char temp[30];
for(i=0;i<n-1;i++)
    for(j=i+1;j<n;j++)
        if(strcmp(emp[i].position,emp[j].position)>0) {strcpy(temp,emp[i].position);
                                                 strcpy(emp[i].position,emp[j].position);
                                                 strcpy(emp[j].position,temp);}

}

void age(data *emp; int n;){
int i,j, temp;
for(i=0;i<n-1;i++)
    for(j=i+1;j<n;j++){
        if(emp[i].age>emp[j].age) {temp=emp[i].age;
                                   emp[i].age=emp[j].age;
                                   emp[j].age=temp;}
    }

}

void sex(data *emp; int n;){
int i,j;
char temp;
for(i=0;i<n-1;i++)
    for(j=i+1;j<n;j++){
        if(emp[i].sex!=emp[j].sex) {temp=emp[i].sex;
                                   emp[i].sex=emp[j].sex;
                                   emp[j].sex=temp;}
    }

}

void show(data *emp; int n;){
int i;
printf("\nHere are sorted lists:\n\n");
for(i=0;i<n;i++){
    printf("\n[%d]",i+1);
    printf("\t%s",emp[i].names);
    printf("\t%d",emp[i].age);
    printf("\t%s",emp[i].position);
    printf("\t%c",emp[i].sex);}

}