In the world of Errors..;

The  modulo  operation is the same as  the remainder of the division .   a  modulo  b  is  c , means that the remainder when a is divided by b is c.It is represented by the ‘%’ operator in many programming languages. For eg: 5%2=1 What is the necessary of MODULO 10^9+7 : The largest integer data type in C/C++ is the  long long int ; its size is 64 bits and can store integers from ( –2^63 ) to ( +2^63 -1 ) . Integers as large as  9 X 10^18  can be stored in a  long long int . But in problems like calculating the number of permutations of a size n array, even this large range may prove insufficient. We know that the number of permutations of a size n array is  n! . Even for a small value of n, the answer can be very large. Eg, for n=21, the answer is 21! which is about 5 x 10^19 and too large for a long long int variable to store. This makes calculating values of large factorials difficult. So, instead of asking th...

#include <stdio.h> int main() {     char str[100];     int i;     gets(str);     for(i=0;str[i]!=NULL;i++)     {     if(str[i]>='A'&&str[i]<='Z')     {     str[i]+=32;     }     else if(str[i]>='a'&&str[i]<='z')     {     str[i]-=32;     }     }     printf("%s",str);     return 0; }