[Water] wikioi2624 square count

This question is called the p1307 black square on vijos, but I prefer wikioi because he has better details ......

 

Description Description

One day seekdreamer went out to play and saw that the floor on the street was composed of many small squares. Suddenly, I was wondering how many squares I Wanted To summarize ......

So he tried to count the number and finally learned that the total side length of a square is N. Your task is to find out the number of squares with at least one side length.

Input description Input description

A natural number n.

Output description Output description

An integer, that is, the total number of squares.

Sample Input Sample Input

2

Sample output Sample output

5

Data range and prompt Data size & hint

(0 ≤ n ≤32767)

Thinkings

Although the range given by this question is only int, It is terrible to multiply! C ++ does not enable long. Using Int Is the rhythm of death... Wa: 70 times here

The formula or enumeration can all be dropped and all have code ..

Code Codes

program ss;  var all:qword;      n,d,i:longint;  begin    readln(n);    all:=0;    for i:=0 to n-1 do     begin      d:=n-i;      d:=d*d;      all:=all+d;     end;    writeln(all);  end.

The above is the formula of Pascal ..

The formula of C will not be put, but it will be the same...

#include<iostream>using namespace std;int main(){    long long n,d,all,i;    cin>>n;    all=0;    for (i=1;i<=n;i++)     {        all+=(n-i+1)*(n-i+1);     }    cout<<all<<endl;}    

This is an enumeration algorithm of C ++. (⊙ v ⊙) Well, most people may think of this as a habit ....