【Codeforces Round #430 (Div. 2) B】Gleb And Pizza

【鏈接】點擊打開鏈接

【題意】

在這里寫題意

【題解】

根據圓心到原點的距離這個東西判斷一下圓在不在那個環里面就好

【錯的次數】

0

【反思】

在這了寫反思

【代碼】

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <cstdlib>
#include <cmath>
using namespace std;
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define LL long long
#define rep1(i,a,b) for (int i = a;i <= b;i++)
#define rep2(i,a,b) for (int i = a;i >= b;i--)
#define mp make_pair
#define pb emplace_back
#define fi first
#define se second
#define ld long double
#define ms(x,y) memset(x,y,sizeof x)
#define ri(x) scanf("%d",&x)
#define rl(x) scanf("%lld",&x)
#define rs(x) scanf("%s",x)
#define rf(x) scnaf("%lf",&x)
#define oi(x) printf("%d",x)
#define ol(x) printf("%lld",x)
#define oc putchar(' ')
#define os(x) printf(x)
#define all(x) x.begin(),x.end()
#define Open() freopen("F:\\rush.txt","r",stdin)
#define Close() ios::sync_with_stdio(0)
#define sz(x) ((int) x.size())
#define ld long doubletypedef pair<int,int> pii;
typedef pair<LL,LL> pll;//mt19937 myrand(time(0));
//int get_rand(int n){return myrand()%n + 1;}
const int dx[9] = {0,1,-1,0,0,-1,-1,1,1};
const int dy[9] = {0,0,0,-1,1,-1,1,-1,1};
const double pi = acos(-1.0);
const int N = 1e5;struct abc{LL x,y,r;
};LL R,D;
int n;
abc a[N+10];LL sqr(LL x){return x*x;
}int main(){//Open();//Close();rl(R),rl(D);ri(n);int ans = 0;rep1(i,1,n) {LL x,y,r;rl(x),rl(y),rl(r);LL temp = sqr(x)+sqr(y);long double temp1 = sqrt(temp)-r,temp2 = sqrt(temp)+r;if ( (R-D) <= temp1 && temp2 <= R) ans++;}oi(ans);puts("");return 0;
}