/*------------------------------------------------------- 功能:从键盘上输入一个字符串, 将该字符串升序排列后输出到文件test.txt 中,然后从该文件读出字符串并显示出来。 -------------------------------------------------------*/ #include "stdio.h" #include "stdlib.h" #include "string.h" main() { FILE *fp; char t,str[100],str1[100]; int n,i,j; if((fp=fopen("test.txt","w"))==NULL) { printf("can't open this file.\n"); exit(0); } printf("input a string:\n"); gets(str); ________________; for(i=0; ________________ ;i++) for(j=0;j if(________________) { t=str[j]; str[j]=str[j+1]; str[j+1]=t; } ________________; fclose(fp); fp=fopen("test.txt","r"); fgets(str1,100,fp); printf("%s\n",str1); fclose(fp); }