start:prog2:lectures:code2
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start:prog2:lectures:code2 [2017/03/02 17:31] kkv created |
start:prog2:lectures:code2 [2022/12/10 09:08] (current) |
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| void (*print)(const struct Person*); | void (*print)(const struct Person*); | ||
| void (*printer)(const struct Person*); | void (*printer)(const struct Person*); | ||
| - | struct Person *This; | ||
| } person1, person2; | } person1, person2; | ||
| Line 77: | Line 76: | ||
| person1.print = print; | person1.print = print; | ||
| person1.printer = print_nice; | person1.printer = print_nice; | ||
| - | person1.This = &person1; | ||
| person2.name = "Petya"; | person2.name = "Petya"; | ||
| Line 83: | Line 81: | ||
| person2.print = print; | person2.print = print; | ||
| person2.printer = print_ugly; | person2.printer = print_ugly; | ||
| - | person2.This = &person2; | ||
| person1.print(&person1); | person1.print(&person1); | ||
| Line 92: | Line 89: | ||
| </code> | </code> | ||
| + | |||
| + | === Universal search === | ||
| + | <code c++> | ||
| + | // Programming 1. Sample at 2018-02-15-14-55.05 | ||
| + | #include <stdio.h> | ||
| + | |||
| + | struct S{ | ||
| + | int a; | ||
| + | int b; | ||
| + | }; | ||
| + | |||
| + | void* search( void *key, | ||
| + | void *arr, | ||
| + | int n, | ||
| + | int size, | ||
| + | int (*comp)(const void *, const void *) | ||
| + | ){ | ||
| + | |||
| + | for(int i=0;i<n;i++){ | ||
| + | if(comp(key, arr+i*size) == 0){ | ||
| + | return arr+i*size; | ||
| + | } | ||
| + | } | ||
| + | return NULL; | ||
| + | } | ||
| + | |||
| + | // if both fields are equal, the structures are equal | ||
| + | // otherwise compare by the sum of two fields | ||
| + | int comp(const void *a, const void *b){ | ||
| + | struct S *aa = (struct S*)a; | ||
| + | struct S *bb = (struct S*)b; | ||
| + | if(aa->a == bb->a && aa->b == bb->b){ | ||
| + | return 0; | ||
| + | } | ||
| + | if((aa->a + aa->b) - (bb->a + bb->b) > 0){ | ||
| + | return 1; | ||
| + | } | ||
| + | return -1; | ||
| + | } | ||
| + | |||
| + | int main(){ | ||
| + | struct S arr[]={{1,2},{3,4},{5,6},{6,7}}; | ||
| + | struct S* value; | ||
| + | struct S key={5,6}; | ||
| + | |||
| + | value = search(&key, arr, 4, sizeof(struct S), comp); | ||
| + | if(value){ | ||
| + | printf("%zu\n", value - arr); | ||
| + | }else{ | ||
| + | printf("nooooo\n"); | ||
| + | } | ||
| + | return 0; | ||
| + | } | ||
| + | |||
| + | </code> | ||
| + | |||
start/prog2/lectures/code2.1488475905.txt.gz · Last modified: 2022/12/10 09:08 (external edit)
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