第一题可以用 log(); （求对数值） abs();（求绝对值）搞定:lol:
第二题可以用qsort(),把源Array重整。而且重整以后还可以使用bsearch()来搜索。:q```+
/*man qsort*/
[quote]
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
static int
cmpstringp(const void *p1, const void *p2)
{
/* The arguments to this function are "pointers to
pointers to char", but strcmp() arguments are "pointers
to char", hence the following cast plus dereference */
return strcmp(* (char **) p1, * (char **) p2);
}
int
main(int argc, char *argv[])
{
int j;
assert(argc > 1);
qsort(&argv[1], argc - 1, sizeof(char *), cmpstringp);
for (j = 1; j < argc; j++)
puts(argv[j]);
exit(EXIT_SUCCESS);
}
[/quote]
/*man bsearch*/
[quote]
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct mi {
int nr;
char *name;
} months[] = {
{ 1, "jan" }, { 2, "feb" }, { 3, "mar" }, { 4, "apr" },
{ 5, "may" }, { 6, "jun" }, { 7, "jul" }, { 8, "aug" },
{ 9, "sep" }, {10, "oct" }, {11, "nov" }, {12, "dec" }
};
#define nr_of_months (sizeof(months)/sizeof(months[0]))
static int compmi(const void *m1, const void *m2) {
struct mi *mi1 = (struct mi *) m1;
struct mi *mi2 = (struct mi *) m2;
return strcmp(mi1->name, mi2->name);
}
int main(int argc, char **argv) {
int i;
qsort(months, nr_of_months, sizeof(struct mi), compmi);
for (i = 1; i < argc; i++) {
struct mi key, *res;
key.name = argv[i];
res = bsearch(&key, months, nr_of_months,
sizeof(struct mi), compmi);
if (res == NULL)
printf("â%sâ: unknown month\n", argv[i]);
else
printf("%s: month #%d\n", res->name, res->nr);
}
return 0;
}
[/quote]
[color=red]刚学新语言的话所有方法都要试都要写，学好了以后就要学会多用Lib（除非你的汇编也很牛）和Copy&Paste[/color]
[[i] 本帖最后由 lazyman 于 2007-1-13 11:00 编辑 [/i]]