char *fputs(char *s, int n, FILE *fp)
int fputs(char *s, FILE *fp)
fgets正常时返回读取字符串的首地址,出错或文件尾,返回NULL。
fputs正常时返回写入的最后一个字符,出错返回EOF。
#define _CRT_SECURE_NO_WARNINGS #include<stdio.h> #include <stdlib.h> #include <time.h> //文件排序 //内存排序 void main1() { time_t ts; unsigned int num = time(&ts);//获取随机数种子 srand(num); int a[100]; for (int i = 0; i < 100;i++) { a[i] = rand() % 100; } FILE *pf = fopen("C:\\1.data", "wb"); fwrite(a, sizeof(int), 100, pf); fclose(pf); system("pause"); } int com(void *p1, void *p2) { int *pint1 = p1; int *pint2 = p2; if (*pint1 >*pint2) { return 1; //大于 } else if (*pint1 <*pint2) { return -1;//小于 } else { return 0; } //> 1,0 } //读取到内存,然后排序 void memsort() { int *p = malloc(400); int *pread = malloc(400); FILE *pf = fopen("C:\\1.data", "rb+"); fread(p, sizeof(int), 100, pf); for (int i = 0; i < 100; i++) { printf("\n%d", p[i]); } fflush(pf);//刷新,生效 qsort(p, 100, 4, com);//排序 printf("sort later\n"); for (int i = 0; i < 100; i++) { printf("\n%d", p[i]); } rewind(pf); fwrite(p, sizeof(int), 100, pf); fflush(pf);//刷新,生效 rewind(pf); fread(pread, sizeof(int), 100, pf); fflush(pf);//刷新,生效 for (int i = 0; i < 100;i++) { printf("\npread=%d", pread[i]); } fclose(pf); } void fileread() { FILE *pf = fopen("C:\\1.data", "rb"); for (int i = 0; i < 100;i++) { int num; fseek(pf,i*sizeof(int) , SEEK_SET);//i顺序,99-i逆序 fread(&num, sizeof(int), 1, pf); if (num==3) { printf("%d", num);//顺序查找 100 } printf("\nnum=%d", num); } fclose(pf); } void binsearch(int findnum) { FILE *pf = fopen("C:\\1.data", "rb"); int tou = 0; int wei = 99; int flag = 0; int ci = 0; while (tou<=wei) { ci++; int zhong = (tou + wei) / 2; //a[zhong] int zhongdata; fseek(pf,zhong*sizeof(int), SEEK_SET);//i顺序,99-i逆序 fread(&zhongdata, sizeof(int), 1, pf); if (findnum==zhongdata) { flag = 1;//找到 printf("\n找到%d", zhongdata); break; } else if (findnum > zhongdata) { tou = zhong + 1; } else { wei = zhong - 1; } } if (flag) { printf("找到了\n"); } else { printf("没找到了\n"); } printf("找了%d次",ci); fclose(pf); } void main3x() { //memsort(); //fileread(); fileread(); while (1) { int findnum; scanf("%d", &findnum); binsearch(findnum); } system("pause"); } void randwirte() { time_t ts; unsigned int num = time(&ts);//获取随机数种子 srand(num); int a[100]; for (int i = 0; i < 100; i++) { a[i] = rand() % 100; } FILE *pf = fopen("C:\\sort.data", "wb"); fwrite(a, sizeof(int), 100, pf); fclose(pf); } void showfile() { int *p = malloc(400); FILE *pf = fopen("C:\\sort.data", "rb"); fread(p, sizeof(int), 100, pf); for (int i = 0; i < 100; i++) { printf("\n%d", p[i]); } fclose(pf); } void main() { //showfile(); showfile(); printf("\n排序以后"); FILE *pf = fopen("C:\\sort.data", "rb+"); for (int i = 0; i < 100 - 1;i++) { for (int j = 0; j < 100 - 1 - i;j++) { int dataj = 0; fseek(pf, sizeof(int)*j, SEEK_SET); fread(&dataj, sizeof(int), 1, pf); int dataj1 = 0; fseek(pf, sizeof(int)*(j+1), SEEK_SET); fread(&dataj1, sizeof(int), 1, pf); if (dataj <dataj1) { fseek(pf, sizeof(int)*(j + 1), SEEK_SET); fwrite(&dataj, 4, 1, pf); fseek(pf, sizeof(int)*j, SEEK_SET); fwrite(&dataj1, 4, 1, pf); } /*if (a[j]<a[j+1]) { swap(a[j] a[j+1]) }*/ } } fclose(pf); showfile(); system("pause"); }
时间: 2024-11-05 18:51:15