1 #include<iostream>

 2 //#include<stdio.h>

 3 using namespace std;

 4

 5 int main() {

 6     FILE* pFile = fopen("digits.txt","r");

 7     if(pFile == NULL){

 8         cout << "打开文件失败!" << endl;

 9         return 0;

10     }

11     //unsigned int res = 1;

12     long long res = 1;

13     while(!feof(pFile)) {

14

15         char cnums[14];

16         bool end = false;

17         bool has_n = false;

18         for(int i = 0; i < 14; i++) {

19             if(feof(pFile)){

20                 end = true;

21                 break;

22             }

23             if(i == 13 && has_n == false){

24                 break;

25             }

26             char c = fgetc(pFile);

27             if(c == '\n'){

28                 has_n = true;

29             }

30             cnums[i] = c;

31         }

32         if(end)

33             break;

34         //要考虑是否有'/n'和'0'

35         //unsigned int m = 1;

36         long long m = 1;

37         bool haszero = false;

38         int j=0;//可能要用来表示0的位置

39         int k = 13;

40         if(has_n){

41             k = 14;

42         }

43         for(j = 0; j<k;j++) {

44             if(cnums[j] != '0' && cnums[j] != '\n') {

45                 m = m*(cnums[j]-'0');

46             }

47             else if (cnums[j] == '0'){

48                 haszero = true;

49                 break;//13个数字中含有0

50             }

51         }

52         if(haszero == false) {//13个数字中不含0，比较结果，并返回指针

53             if(m > res){

54                 res = m;

55             }

56             fseek(pFile, -(k-1), SEEK_CUR );

57             //cout << fgetc(pFile);

58         } else {//13个数字中含有0，将指针返回到0之后

59             fseek(pFile, -k, SEEK_CUR );

60             fseek(pFile, j+1, SEEK_CUR );

61             //cout << fgetc(pFile);

62         }

63         cout << res << endl;

64     }

65     cout << res;

66     if(fclose(pFile) == EOF) {

67         cout << "关闭文件失败." << endl;

68     }

69     system("pause");

70     return 0;

71 }