c++ - How can I change my program by using a summing statement instead? -
my c++ assignment write program display population estimate of each of countries (mexico , us) year, 1985 present. round population nearest whole number , display information in 3 columns. after doing that, modify program display same information when mexico's population exceeds population. did program correctly, when ran it gave me correct information , professor gave me 0 credit because wants me not use pow function summing statement, don't know how can that, sounds more complicated me. program wrote way don't know how change using summing statement:
//program compute when mexico's pop exceeds pop #include<iostream> #include<cmath> #include<iomanip> using namespace std; int main() { int years; double uspop, mxpop; cout<<setw(7)<<"year"<<setw(13)<<"us pop"<<setw(13)<<"mex pop"<<endl; cout<<setprecision(0)<<fixed; for(years=1985;years<=2014;years++) { uspop=243000000.0*(pow(1.007,(years-1984))); mxpop=78000000*pow(1.033,(years-1984)); cout<<setw(7)<<years<<setw(13)<<uspop<<setw(13)<<mxpop<<endl; } }
i not sure mean "summing statement", since doesn't problem needs "+" operation.
in case don't have use pow
, can overwrite , mex population number @ each iteration multiply using indicator.
below example:
int main() { int years; double uspop=243000000.0; double mxpop=78000000; cout<<setw(7)<<"year"<<setw(13)<<"us pop"<<setw(13)<<"mex pop"<<endl; cout<<setprecision(0)<<fixed; double usindicator = 1.007; double mexindicator = 1.033; for(years=1985;years<=2014;years++) { uspop=uspop*usindicator; mxpop=mxpop*mexindicator; cout<<setw(7)<<years<<setw(13)<<uspop<<setw(13)<<mxpop<<endl; } }