[Codeforces Round495A] Sonya and Hotels

[题目链接]

        https://codeforces.com/contest/1004/problem/A

[算法]

         直接按题意模拟即可

         时间复杂度 ：O(NlogN)

[代码]

      

#include<bits/stdc++.h>
using namespace std;
#define MAXN 110
const int inf = 1e9;

int n,d;
int a[MAXN];
set< int > ans;

template <typename T> inline void read(T &x)
{
    T f = 1; x = 0;
    char c = getchar();
    for (; !isdigit(c); c = getchar()) if (c == '-') f = -f; 
    for (; isdigit(c); c = getchar()) x = (x << 3) + (x << 1) + c - '0';
    x *= f;
}
inline bool ok(int x)
{
        int i;
        int ret = inf;
        for (int i = 1; i <= n; i++) ret = min(ret,abs(a[i] - x));
        return ret == d;
}

int main() 
{
        
        read(n); read(d);
        for (int i = 1; i <= n; i++) read(a[i]);
        for (int i = 1; i <= n; i++)
        {
                if (ok(a[i] - d)) ans.insert(a[i] - d);
                if (ok(a[i] + d)) ans.insert(a[i] + d);
        }
        printf("%d\n",(int)ans.size());
        
        return 0;
    
}