PAT（甲级）2019年春季考试题解

本来想用PAT抵浙大的机试成绩，结果忘记时间错过了报名春季的考试（其实是只刷了十几题心里没底想晚点再报名，后来就忘记了）…然后看题库发现现在PTA平台不会同步更新最新的考试题目了，要去教育超市花钱买（稍微有点坑），不过好处是花了钱我才能更加重视…于是在今天–在考前的一周，下午一点半准时模拟了下周的考试，所幸练习的结果不错，要是考试也能有这样的发挥就好了。7-1 Sexy Primes (20 分)Sexy primes are pairs of primes of the form (p, p+6), so-named since “sex” is the Latin word for “six”. (Quoted from http://mathworld.wolfram.com/SexyPrimes.html)Now given an integer, you are supposed to tell if it is a sexy prime.Input Specification:Each input file contains one test case. Each case gives a positive integer N (≤1 0 8 10^8108​​ ).Output Specification:For each case, print in a line Yes if N is a sexy prime, then print in the next line the other sexy prime paired with N (if the answer is not unique, output the smaller number). Or if N is not a sexy prime, print No instead, then print in the next line the smallest sexy prime which is larger than N.Sample Input 1:47Sample Output 1:Yes41Sample Input 2:21Sample Output 2:No23#includeiostream#includevector#includequeue#includealgorithm#includestring#includecstring#includeunordered_map#includeunordered_setusingnamespacestd;constintmaxn=100;constintINF=0x3f3f3f3f;boolisprime(longlonga){if(a=1)returnfalse;for(longlongi=2;i*i=a;i++){if(a%i==0)returnfalse;}returntrue;}intmain(){intn;scanf("%d",n);if(isprime(n)){if(isprime(n-6))printf("Yes\n%d",n-6);elseif(isprime(n+6))printf("Yes\n%d",n+6);else{for(inti=n+1;;i++){if(isprime(i)(isprime(i+6)||isprime(i-6))){printf("No\n%d",i);break;}}}}else{for(inti=n+1;;i++){if(isprime(i)(isprime(i+6)||isprime(i-6))){printf("No\n%d",i);break;}}}return0;}7-2 Anniversary (25 分)Zhejiang University is about to celebrate her 122th anniversary in 2019. To prepare for the celebration, the alumni association （校友会） has gathered the ID’s of all her alumni. Now your job is to write a program to count the number of alumni among all the people who come to the celebration.Input Specification:Each input file contains one test case. For each case, the first part is about the information of all the alumni. Given in the first line is a positive integer N (≤1 0 5 10^5105​​ ). Then N lines follow, each contains an ID number of an alumnus. An ID number is a string of 18 digits or the letter X. It is guaranteed that all the ID’s are distinct.The next part gives the information of all the people who come to the celebration. Again given in the first line is a positive integer M (≤1 0 5 10^5105​​ ).Then M lines follow, each contains an ID number of a guest. It is guaranteed that all the ID’s are distinct.Output Specification:First print in a line the number of alumni among all the people who come to the celebration. Then in the second line, print the ID of the oldest alumnus – notice that the 7th - 14th digits of the ID gives one’s birth date. If no alumnus comes, output the ID of the oldest guest instead. It is guaranteed that such an alumnus or guest is unique.Sample Input:537292819690611871061048119780620221344068419861215041713072819571002001X1507021936041909126530125197901260019150702193604190912220221196701020034610481197806202213440684198612150417370205198709275042Sample Output:3150702193604190912#includeiostream#includevector#includequeue#