I'm reading the book "Programming Challenges: The Programming Contest Training Manual" and are implementing a problem where I do not understand the use of operators c>>1 and the comparison if (n&1), someone could help me to know they mean?

this is the example code

#include <stdio.h>

#define MAX_N 300
#define MAX_D 150

long cache[MAX_N/2][2];

void make_cache(int n,int d,int mode)
{
    long tmp[MAX_D];
    int i,count;

    for(i=0;i<MAX_D;i++) tmp[i]=0;

    tmp[0]=1;count=0;

    while(count<=n)
    {
        count++;

        for(i=(count&1);i<=d;i+=2)
        {
            if(i)
                tmp[i] = tmp[i-1] + tmp[i+1];
            else if(!mode)
                tmp[0]=tmp[1];
            else
                tmp[0]=0;
        }

        if((count&1)==(d&1))
            cache[count>>1][mode]=tmp[d];
    }
}

int main()
{
    int n,d,i;
    long sum;

    while(1)
    {
        scanf("%d %d",&n,&d);

        if(n&1)
            sum=0;
        else if(d==1)
            sum=1;
        else if(n<(d<<1))
            sum=0;
        else if(n==(d<<1))
            sum=1;
        else
        {
            make_cache(n,d,0);
            make_cache(n,d,1);
            sum=0;

            for(i=0;i<=(n>>1);i++)
                sum+=cache[i][0]*cache[(n>>1)-i][1];
        }

        printf("%ld\n",sum);
    }

    return 0;
}