哪位大神能够帮忙写一下这两道题的步骤

前面这个相当于一个互逆运算；后面这个定积分是常数，常数的导数是零。

#include "stdio.h"
#include "string.h"
//从键盘输入两个字符串，找出其中没有同时出现在两个字符串中的字符。
//eg: abcd&&bdfg -------- abfg
main()
{
char a[100];
char b[100];
char c[100] = {0};
char d[100] = {0};
printf("请输入字符串a:\n");
scanf("%s", a);
printf("请输入字符串b:\n");
scanf("%s", b);
int n = strlen(a);
int m = strlen(b);
int k = 0;
int i, j;
for(i = 0; i < n; ++i) //选出字符串a中独有的字符
{
int judge = 1;
for(j = 0; j < m; ++j)
{
if(a[i] == b[j])
{
judge = 0;
return 0;
}
}
if(judge == 0)
continue;
c[i] = a[i];
}
for(i = 0; i < m ; ++i) //选出字符串b中独有的字符
{
int judge = 1;
for(j = 0; j < n; ++j)
{
if(b[i] == a[j])
{
judge = 0;
return 0;
}
}
if(judge == 0)
continue;
d[i] = b[i];
}
int n1 = strlen(c);
for(i = 0; i < n1; ++i)
printf("%c", c[i]);
int n2 = strlen(d);
for(i = 0;i < n2; ++i)
printf("%c", d[i]);
}