#include <stdio.h> #include <string.h> #include <stdlib.h> void *binary_search (void *arr, void *value, int len, int mem, int(*compare)(void *, void *)) { int low = 0; int high = len-1; int mid; while(low <= high) { mid = (low + high) / 2; void* addr = (char*)arr + mid * mem; if (compare(addr, value) == 0) { return addr; } else if (compare(addr, value) > 0) { high = mid - 1; } else { low = mid + 1; } } return NULL; } int cmp_int (void* x, void* y) { int *a = (int*)x; int *b = (int*)y; return *a - *b; } int cmp_string (void* x, void* y) { char *a = *(char**)x; char *b = *(char**)y; return strcmp(a, b); } int main (int argc, char **argv) { //查找整数 int arr[] = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100}; int num = 10; int value = 10; void* ret = binary_search(arr, &value, num, sizeof(int), cmp_int); if (ret == NULL) { printf("NULL\n"); } else { printf("%d\n", *((int*)ret)); } //查找字符串 char* books[] = {"水浒传", "三国演义", "西游记", "红楼梦"}; char* book = "三国演义"; int len = 4; void* retStr = binary_search(books, &book, 4, sizeof(char *), cmp_string); if (retStr == NULL) { printf("NULL\n"); } else { printf("%s\n", *((char**)retStr)); } return 0; }
通用线性查找:
#include <stdio.h> #include <stdlib.h> #include <memory.h> #include <string.h> void *search (void *a, void *value, int len, int size, int(*cmp)(void*, void*)) { for (int i = 0; i < len; i++) { void *addr = (char *)a + i * size; if (cmp(addr, value) == 0) { return addr; } } return NULL; } int cmp_int(void *x, void *y) { return *(int *)x - *(int *)y; } int cmp_str(void *x, void *y) { return strcmp(*(char **)x, *(char **)y); } int main (int argc, char **argv) { char *books[] = {"水浒传", "三国演义", "西游记", "红楼梦"}; char *book = "西游记"; void *ret_str = search(books, &book, 4, sizeof(char *), cmp_str); printf("%s\n", *(char **)ret_str); int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; int len = 10; int value = 5; void *ret_int = search(a, &value, len, sizeof(int), cmp_int); printf("%d\n", *(int *)ret_int); return 0; }
通用交换函数:
#include <stdio.h> #include <memory.h> void swap (void *a, void *b, int size) { char tmp[size]; memcpy(tmp, a, size); memcpy(a, b, size); memcpy(b, tmp, size); } int main (int argc, char **argv) { int x = 36, y = 72; swap(&x, &y, sizeof(int)); printf("%d %d\n", x, y); double p = 3.1415926, e = 2.7182818; swap(&p, &e, sizeof(double)); printf("%lf %lf\n", p, e); char *s1 = strdup("倚天剑"); char *s2 = strdup("屠龙刀"); swap(&s1, &s2, sizeof(char *)); printf("%s %s", s1, s2); return 0; }
通用栈:
#include <stdio.h> #include <stdlib.h> #include <memory.h> #include <string.h> typedef struct { int *elem; int len;//栈中元素的个数 int volume; int size; } stack; void init (stack *s, int size) { s->len = 0; s->volume = 3; s->size = size; s->elem = malloc(s->volume * s->size); } void push (stack *s, void *value) { if (s->len == s->volume) { s->volume *= 2; s->elem = realloc(s->elem, s->volume * s->size); } void *addr = (char *)s->elem + s->len * s->size; memcpy(addr, value, s->size); s->len++; } void pop (stack *s, void *value) { void *addr = (char *)s->elem + (s->len - 1) * s->size; memcpy(value, addr, s->size); s->len--; } int main (int argc, char **argv) { int cards[5] = {3, 7, 1, 2, 4}; stack s; init (&s, sizeof(int)); for (int i = 0; i < 5; i++) { push(&s, &cards[i]); } for (int i = 0; i < 5; i++) { pop(&s, &cards[i]); } for (int i = 0; i < 5; i++) { printf("%d\n", cards[i]); } char *books[4] = {"西游记", "三国演义", "水浒传", "红楼梦"}; stack st; init(&st, sizeof(char *)); for (int i = 0; i < 4; i++) { char *book = strdup(books[i]); push(&st, &book); } char *name; for (int i = 0; i < 4; i++) { pop(&st, &name); printf("%s\n", name); free(name); } }