有一个文件里面都是一行一行的数字，用空格分开，请把它每行转化成一个链表。
注意getline(ifstream, line)得到一行，而且使用了头结点。
https://gist.github.com/Jiacai/9431341
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#include <string>#include <fstream>#include <iostream>using
namespace std;struct
ListNode { int
val; ListNode *next; ListNode(int
_val) { val = _val; next = NULL; }};/* 123 456*/void
readFile(string fileName, ListNode** list, int
lineLimit) { ifstream ifstrm(fileName); if(!ifstrm) { exit(1); } int
i = 0; string line; while
(getline(ifstrm, line) && i < lineLimit) { // parse this line ListNode* dummy = new
ListNode(0); ListNode *last = dummy; int
idx = 0; while
(idx < line.length()) { // skip spaces while
(idx < line.length() && line[idx] == ‘ ‘) { idx++; } if
(idx == line.length()) break; int
num = 0; while
(idx < line.length() && line[idx] != ‘ ‘) { num = num * 10 + line[idx] - ‘0‘; idx++; } ListNode* node = new
ListNode(num); last->next = node; last = node; } last->next = NULL; list[i] = dummy->next; delete
dummy; i++; } ifstrm.close();}int
main() { const
int LINE_COUNT = 100; ListNode* list[LINE_COUNT]; memset(list, 0, sizeof(list)); readFile("d:\\test.txt", list, LINE_COUNT); for
(int i = 0; i < LINE_COUNT; i++) { ListNode* current = list[i]; if
(current == NULL) break; while
(current != NULL) { cout << current->val << "->"; current = current->next; } cout << "NULL"
<< endl; } system("pause");} |
原文：http://www.cnblogs.com/lautsie/p/3588733.html