这道练习题训练了:
1.结构体数组
2.二分查找
3.指针操作
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都不难,但很基础,我觉得很好,做完了记到博客上来,题目见k&R,实现如下:
/* * Practice of struct array. K&R 6-1 * @author : wusuopubupt * @date : 2014-09-18 */ #include <stdio.h> #include <ctype.h> #include <string.h> #define MAXWORD 100 typedef struct key_{ char *word; int count; } key; key key_tab[] = { {"auto", 0}, {"break", 0}, {"case", 0}, {"char", 0}, {"const", 0}, {"continue", 0}, {"default", 0}, {"for", 0}, {"int", 0}, {"void", 0}, {"while", 0} }; int getword(char *word, int n); int binary_search(key key_tab[], char *word, int n); int main() { int i; int n_keys = sizeof(key_tab) / sizeof(key_tab[0]); char word[MAXWORD]; while(getword(word, MAXWORD) != EOF) { if(isalpha(word[0])) { if((i = binary_search(key_tab, word, n_keys)) >= 0) { key_tab[i].count++; } } } i = 0; while(i < n_keys) { printf("%s : %d\n", key_tab[i].word, key_tab[i].count); i++; } return 0; } int getword(char *word, int n) { int c; char *w = word; while(isspace(c = getchar())) { ; } if(c != EOF) { *w++ = c; } if(!isalpha(c)) { *w = '\0'; return c; } while(n > 0) { c = getchar(); if(isalnum(c)) { *w++ = c; } else { break; } n--; } *w = '\0'; return w[0]; } int binary_search(key key_tab[], char *word, int n) { int low = 0; int high = n-1; int mid; int result; while(low <= high) { mid = (low+high) / 2; result = strcmp(word, key_tab[mid].word); if(result < 0) { high = mid-1; } else if(result > 0) { low = mid + 1; } else { return mid; } } return -1; }
github:https://github.com/wusuopubupt/LearningC/blob/master/K%26R/chp6/keyword_count.c
时间: 2024-10-13 11:27:22