# include & ltstdlib.h & gt
# include & ltstring.h & gt
# Definition number 10
Structural city
{
char CN[ 100]； //City name
Int SH// Total number of housing units in the city
Int SP// Total number of households in the city
Double AvgP// Number of houses per household
} ten _ city[N]；
void paixu()
{
int t_SH，t_SP，j=0，I；
Double t _ AvgP
char t _ CN[ 100]；
while(j & lt； n)
{
for(I = j+ 1； I & ltn；; i++)
{
If (ten _ cities [j]. AvgP & gt Ten cities. AvgP)
{
t_SH = ten_city[i]。 SH；
t_SP = ten_city[i]。 SP；
t_AvgP = ten_city[i]。 AvgP
strcpy(t_CN，ten_city[i])。 CN)；
Ten cities. SH = ten_city[j]。 SH；
Ten cities. SP = ten_city[j]。 SP；
Ten cities. AvgP = ten_city[j]。 AvgP
strcpy(ten_city[i].CN，ten_city[j]。 CN)；
X _ city [j]. SH = t _ SH
X _ city [j]. SP = t _ SP
X _ city [j]. AvgP = t _ AvgP
strcpy(ten_city[j].CN，t _ CN)；
}
}
printf("\n%s\t%d\t%d\t%f "，ten_city[j]。 CN，ten_city[j]。 SH，ten_city[j]。 SP，ten_city[j]。 AvgP)；
j++；
}
}
void main()
{
int I；
Printf ("\ nName: # #, Student ID: # #, Class: # # #");
for(I = 0； I & ltn；; i++)
{
Printf ("\ nPlease enter the city name %d:", i+1);
Get (ten_city[i]. CN)；
Printf ("\ nPlease enter the total number of housing units in city %d:", i+1);
Scanf("%d ",&Ten cities. SH)；
Printf ("Please enter the total number of households in city %d:", I+1);
Scanf("%d ",&Ten cities. SP)；
getchar()； //Clear the carriage return entered by scanf.
Ten cities. AvgP = (double)ten_city[i]。 SH/(double)ten_city[i]。 SP；
}
Printf ("\ nRanked according to the number of houses from low to high: \ nCity order \ tTotal number of houses \ tTotal number of families \ tAverage number of houses \ n");
Paixu ();
printf(" \ n \ n ")；
}
The above procedures can be run directly!
I hope it helps you.