I know I have written stupid code and I am getting timeout for all test cases except 1. My program time compexity is o(n^2) as I have used 2 for loop. Can someone suggest better solution and try to explain why I am getting timeout error?

int i,j,r,k,t,count;
/* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
scanf("%d",&t);
while(t--){
    scanf("%d%d",&r,&k);
    count=0;
    for(i=0;i<=sqrt(r);i++){
        for(j=1;j<=sqrt(r);j++){
            if(i*i+j*j==r)count++;
        }
    }    
    //printf("%d\n",count*4);    
    (count*4<=k)?printf("possible\n"):printf("impossible\n");        
}    
return 0;