The first question: #include?
//?Find the sum of the elements before the first odd number of the integer array?a?, n? is the length of the array< /p>
int?sum_before_first_odd_num(int*?a,?int?n)
{
int?i,?sum?=?0;
for?(i?=?0;?i?
{
if?(a[i]?&?1 ?=?0)?//?odd number
{
break;
}
sum?+=?a[ i];
}
return?sum;
}
int?main(int?argc,?char**? argv)
{
int?i,?n,?a[100];?//?Assume that?n?is maximum?100
printf ?("The size of the array you want to input:");
scanf?("%d",?&n);
for?(i?=?0;? i?
{
scanf?("%d",?&a[i]);
}
int?sum?=?sum_before_first_odd_num(a,?n);
printf?("The sum of the elements before the first odd number is: %d\n",?sum);< /p>
return?0;
}
Run:
Second question: #include?
#include?
//?Ascending comparison function
int?cmp_asc?(const?void*?a,?const?void*?b )
{
int?i1?=?*((int*)a);
int?i2?=?*((int*) b);
return?i1?-?i2;
}
//?Descending comparison function
int?cmp_desc? (const?void*?a,?const?void*?b)
{
int?i1?=?*((int*)a);
int?i2?=?*((int*)b);
return?i2?-?i1;
}
int? main(int?argc,?char**?argv)
{
int?i,?n,?a[100];?//?Assume?n?No More than?100
printf?("The size of the array you want to input:");
scanf?("%d",?&n);
for?(i?=?0;?i?
{
scanf?("%d",?&a[i]);
}
int?half?=?n?/?2;
qsort(a,?half?,?sizeof(a[0]) ,?cmp_asc);?//?The first half of the elements are sorted in ascending order
qsort(a?+?half,?n?-?half,?sizeof(a[0]),?cmp_desc);? //?The second half of the elements are sorted in descending order
printf?("\nThe first half of the sorted array:\n");
for?(i?=?0;? i?
{
printf?("%d?",?a[i]);
}
printf?("\nThe second half of the sorted array:\n");
for?(i?=?half;?i?
{
printf?("%d?",?a[i]);
}
printf?("\ n");
return?0;
}
Run:
Question 3: #include?
#include?
void?count_num_in_str(char*?s,?int*?a)
{
int?i;
for?(i?=?0;?i?
{
a[i]?=?0;
}
char*?c?=?s;
while?(*c ?=?'\0')
{
if?(*c?>=?'0'?&&?*c?<='9')?/ /?The current character is a numeric character
{
a[*c?-?'0']++;
}
c++;
}
}
int?main(int?argc,?char**?argv)
{< /p>
printf?("Please enter a string:\n");
char?s[100];?//?Assume that the longest input string is?100< /p>
gets(s);?//?Input
int?i,?a[10];
count_num_in_str(s,?a);
p>for?(i?=?0;?i?
{
printf?("The number of %d? is ?%d?piece\n",?i,?a[i]);
}
return?0;
}
Run: