/* candidatenum.c ：給候選人投票 */
#include "stdio.h"
void Vote()
 {
    int i,j,k;
    long candidatenum;    /*存儲(chǔ)用戶輸入的要投票的候選人序號(hào)*/
    /*輸入各項(xiàng)修改后信息*/
    long Number;
    candidate TmpS;   /*定義進(jìn)行操作時(shí)的臨時(shí)結(jié)構(gòu)體變量*/
    candidate s[10];/*10個(gè)候選人 */
    int recNumber;
    char DataFile[40] = "",next;
    /*DataFile存儲(chǔ)候選人信息的文件名，next為是否進(jìn)行下一次投票操作的選項(xiàng)*/
    FILE *fp;/*====fp指針指向存儲(chǔ)數(shù)據(jù)的文件名====*/
    /*提示用戶輸入要進(jìn)行投票的文件名*/
    printf("\nplease input the name of file where data is stored,end with enter key.\n");
    gets(DataFile);
    /*提示用戶輸入要進(jìn)行投票的文件名*/
    while(*DataFile == ('\0'))
    {
        printf("\nplease input the name of file where data is stored,end with enter key.\n");
        gets(DataFile);
    }
begin:
    /*以讀的方式打開文件，如文件不存在，提示錯(cuò)誤*/
    fp=fopen(DataFile,"rb");
    if (fp == NULL)
    {
        printf("\nOpen file %s fail!End with any key\n",DataFile);
        perror("Open file fail");
        getch();
        exit(1);
    }
    printf("please input the candidate's seatnum which you will vote:");
    scanf("%ld",&candidatenum);
    printf("the candidate you will vote is:%ld\n",candidatenum);
    /*輸入要修改記錄的各項(xiàng)內(nèi)容值，用戶每調(diào)用一次該函數(shù)，給該候選人票數(shù)加1*/
    Number=candidatenum;
   /*將文件中要修改的信息存入結(jié)構(gòu)體數(shù)組*/
   recNumber=0;
   /*循環(huán)將文件數(shù)據(jù)讀入結(jié)構(gòu)體數(shù)組，
   如文件中的數(shù)據(jù)候選人號(hào)和要投票的候選人號(hào)不符，則原樣寫入數(shù)組，
   如文件中數(shù)據(jù)的候選人號(hào)和要投票候選人號(hào)匹配，
   則根據(jù)其他信息如序號(hào)、姓名、簡介等仍原樣寫入數(shù)組，但票數(shù)加一后寫入數(shù)組，即修改。*/
    while((fread(&TmpS,sizeof(candidate),1,fp)) != (int)NULL)
    {
        if(TmpS.Number!=candidatenum)
            {
            s[recNumber].Number = TmpS.Number;
            strcpy(s[recNumber].Name, TmpS.Name);
            strcpy(s[recNumber].intro,TmpS.intro);
            s[recNumber].votenum = TmpS.votenum;

            recNumber++;
            }
        else
            {
            s[recNumber].Number = Number;
            strcpy(s[recNumber].Name, TmpS.Name);
            strcpy(s[recNumber].intro,TmpS.intro);
            s[recNumber].votenum = TmpS.votenum+1;
            /*用戶不可以修改候選人姓名、簡介，所以仍為文件中原值，但票數(shù)加一*/

            recNumber++;
            }
     }
    fclose(fp);
   /*====將修改后的結(jié)構(gòu)體數(shù)組記錄寫入文件====*/
        fp=fopen(DataFile,"wb+");
        if (fp == NULL)
        {
            printf("\nSet up file %sfail !end with anykey.\n",DataFile);
            perror("Set up fail");
            getch();
            exit(1);
        }
        for(i=0; i<recNumber; i++)
        {
            if(fwrite(&s[i],sizeof(candidate),1,fp)!=1)
            {
                printf("\nWrite file %s fail!end with anykey.\n",DataFile);
                perror("Write file fail!");
                    getch();
                    exit(1);
            }
        }
        fclose(fp);
     /*====顯示投票后的得票情況====*/
    fp=fopen(DataFile,"rb");
    if (fp == NULL)
    {
        printf("\nOpen file%sfail!End with any key \n",DataFile);
        perror("Open file fail");
        getch();
        exit(1);
    }
    printf("the file after modify is:\n");
    printf("\nNumber \tName\tvotenum\n");
    while(fread(&TmpS,sizeof(candidate),1,fp) != (int)NULL)
    {
        if(TmpS.Number!=0)
        printf("\n%ld\t%s\t%d\n",TmpS.Number,TmpS.Name,TmpS.votenum);
    }
    fclose(fp);
    /*提示是否進(jìn)行下一次投票*/
    printf("\nGo on ?(y/n)");
    next=getche();
    putchar('\n');
    if ( next =='y' || next =='Y') goto begin;
 }