Facto sum (sum of their factorial modulo 107)

#1

Given N numbers, calculate sum of their factorial modulo 107. (Note it is not 10^7)?
Solution-Some of the test cases are failing
#include
using namespace std;
int main() {
char a[20];
cin>>a;
int sum=0;
for(int i=0;a[i]!=’\0’;i++)
{
int d=1;
for(int j=1;j<=a[i]-‘0’;j++)
d=d*j;
sum=sum+d;
}
cout<<(sum%107);
return 0;
}

#2

https://ide.codingblocks.com/#/s/30134

i removed the errors but it is failing for basic cases like
INPUT:
4
1 2 3 4
OUTPUT:
24
EXPECTED OUTPUT:
33

#3

it has passed ony 2 test cases …and 4 ( 1 2 3 4) is giving correct ans…

#include <bits/stdc++.h>
using namespace std;
int main() {
int a;
cin>>a;
int sum=0;
for(int i=0;i<a;i++)
{
int k;
cin>>k;
int d=1;
for(int j=1;j<=k;j++)
d=d*j;
sum=sum+d;
}
cout<<(sum%107);
return 0;

#4

https://ide.codingblocks.com/#/s/30144

I have made one change and commented it. It should pass all cases now. Do add the problem link so that i can verify first.

1 Like
#5

thank you , i was actually very confused why my one test case wasnt passing, but taking mod at every step helped. Thanks!!

#6

sir my code for the problem is this…but failing the test cases…
#include<bits/stdc++.h>

using namespace std;

int fac(int n)

{int sum=1;
for(int i=2;i<=n;i++)

{

sum=sum*i;

}

return sum;

}

int main() {

int n;

cin>>n;

int count=0;

while(n!=0)

{int a;

cin>>a;

count=count+fac(a);

n–;

}

cout<<count%107;

return 0;

}