Submission #7926861

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define INF 0x3f3f3f3f3f3f3f3f
#define MOD 1000000007
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
const double pi = acos(-1.0);

int n;
int l;

pair<double,double> twoT2P(int twoT){
  double v = pi*twoT/l;
  return make_pair(cos(v),sin(v));
}
int t[3010];

int main(){
  cin>>n>>l;
  rep(i,0,n){
    scanf("%d",t+i);
  }
  double cntX=0;
  double cntY=0;
  rep(i,0,n){
    rep(j,i+1,n){
      pair<double,double> ret;
      {
        ret = twoT2P(t[i]+t[j]);
        cntX+=(n-(j-i+1))*ret.first;
        cntY+=(n-(j-i+1))*ret.second;
      }
      {
        ret = twoT2P(t[i]+t[j]+l);
        cntX+=((j-i-1))*ret.first;
        cntY+=((j-i-1))*ret.second;
      }
    }
  }
  // cnt / 3 / C(n,3) = 2*cnt/n/(n-1)/(n-2)

  printf("%.20lf %.20lf\n",6*cntX/n/(n-1)/(n-2),6*cntY/n/(n-1)/(n-2));
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:24:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",t+i);
                    ^

Judge Result