50 lines
764 B
C++
50 lines
764 B
C++
#include <cstdio>
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#include <cstdlib>
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#include <vector>
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#include <algorithm>
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using namespace std;
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//Written by Coffee. 判断素数
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bool isPrime(int num)
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{
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if (num == 2 || num == 3)
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{
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return true;
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}
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if (num % 6 != 1 && num % 6 != 5)
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{
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return false;
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}
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for (int i = 5; i*i <= num; i += 6)
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{
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if (num % i == 0 || num % (i+2) == 0)
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{
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return false;
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}
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}
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return true;
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}
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int main()
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{
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int n,k;
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vector<int> vec;
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scanf("%d %d",&n,&k);
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int tmp;
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for(int i=0;i<n;i++)
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{
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scanf("%d",&tmp);
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vec.push_back(tmp);
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}
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sort(vec.begin(),vec.end());
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int m=vec.at(n-k)-vec.at(k-1);
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if(isPrime(m))
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{
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printf("YES\n");
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}
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else
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{
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printf("NO\n");
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}
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return printf("%d\n",m),0;
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}
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