the instruction for building this program is not allowing me

to call functions,use iosteam ,use arrays

what they want is just If ,while,for commands , simple variable,only stdio.h

in C

how to transform this code into that??

Code:#include <iostream> unsigned sum_of_divisors(unsigned n) { int result=1; for(unsigned k=2;k*k<=n;++k) { if(n%k==0) { int sum_of_powers=1, power=1; do { power*=k; sum_of_powers+=power; n/=k; } while(n%k==0); result*=sum_of_powers; } } return n>1? (n+1)*result : result; } bool is_abundant(unsigned n) { // The body of this function can be substituted by simply // return sum_of_divisors(n)>2*n; // This is a memoized version. const int cache_size=1000000; static char cache[cache_size]={0}; if(n<cache_size && cache[n]) return cache[n]-1; bool result=(sum_of_divisors(n)>2*n); if(n<cache_size) cache[n] = 1+result; return result; } void print_if_sum_of_abundants(unsigned n) { for(unsigned i=1;i*2<=n;++i) { if(is_abundant(i)&&is_abundant(n-i)) { std::cout << n << " = " << i << " + " << (n-i) << '\n'; return; } } } int main() { int limit; std::cout << "Enter limit: "; std::cin >> limit; for(unsigned i=1;i<=limit;++i) print_if_sum_of_abundants(i); }