# C Program to find union and intersection of two strings

In this program, You will learn how to find union and intersection of two strings in c.

1st is: a b c d e

2nd is: d e f

Union is: a b c d e f

intersection is: d e

## Example: How to find union and intersection of two strings in c

Run it Now
``````#include<stdio.h>
#include<string.h>

void findUnion(char str1[], char str2[]) {

int f, p = 0;
int i, j;

char str3[100];
int len1 = strlen(str1);
int len2 = strlen(str2);

while (str1[p] != '\0') {
str3[p] = str1[p];
p++;
}

for (i = 0; i < len2; i++) {
f = 0;
for (j = 0; j < len1; j++) {
if (str2[i] == str1[j]) {
f = 1;
}
}
if (f == 0) {
str3[p] = str2[i];
p++;
}
}
str3[p] = '\0';
printf("\nUnion of Two String :%s", str3);
}

void findIntersection(char str1[], char str2[]) {

int i, j, k = 0;
char str3[100];

int len1 = strlen(str1);
int len2 = strlen(str2);

for (i = 0; i < len1; i++) {
for (j = 0; j < len2; j++) {
if (str1[i] == str2[j]) {
str3[k] = str1[i];
k++;
}
}
}
str3[k] = '\0';
printf("\nIntersection of Two String :%s", str3);
}

int main() {

char str1[100];
char str2[100];
char str3[100];

printf("Enter First String :");
fgets(str1, 100, stdin);
strtok(str1, "\n");

printf("\nEnter Second String :");
fgets(str2, 100, stdin);
strtok(str2, "\n");

findUnion(str1, str2);
findIntersection(str1, str2);

return 0;
}
``````

#### Output:

``````Enter First String :abc
Enter Second String :bcdef
Union of Two String :abcdef
Intersection of Two String :bc
``````