C++ 中打印最后 10 行的程序
在本教程中,我们将讨论打印最后 10 行的程序。
为此,我们将得到一个包含换行符的字符串,表示下一行的开始。我们的任务是从最后开始,打印从最后开始的全部 10 行。
示例
#include <bits/stdc++.h> using namespace std; #define DELIM '\n' //printing the last 10 lines void print_last_lines(char *str, int n){ if (n <= 0) return; size_t cnt = 0; //storing the number of lines char *target_pos = NULL; //finding the initial position of last line target_pos = strrchr(str, DELIM); if (target_pos == NULL){ cout << "Given string is a single line string"; return; } //moving to the start position of the 1st line while (cnt < n){ //moving to the next lines while (str < target_pos && *target_pos != DELIM) --target_pos; if (*target_pos == DELIM) --target_pos, ++cnt; //if string has less than 10 lines the break else break; } if (str < target_pos) target_pos += 2; cout << target_pos << endl; } int main(void){ char *str1 ="str1\nstr2\nstr3\nstr4\nstr5\nstr6\nstr7\nstr8\nstr9” "\nstr10\nstr11\nstr12\nstr13\nstr14\nstr15\nstr16\nstr17" "\nstr18\nstr19\nstr20\nstr21\nstr22\nstr23\nstr24\nstr25"; print_last_lines(str1, 10); return 0; }
输出
str16 str17 str18 str19 str20 str21 str22 str23 str24 str25
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