PTA 1081~1085

今天总结一下，昨天做的pta的题~

[1081：检查密码](https://pintia.cn/problem-sets/994805260223102976/problems/994805261217153024)

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<string.h>
using namespace std;

int main(){
	int n;
	cin >> n;
	getchar();// 吃回车
	for(int i = 0 ; i < n ; i ++){
		int numa = 0,numn = 0, nump = 0;
		string u;
		getline(cin,u); //getline  
		int len = u.length();
		if(len < 6)
		{
			cout <<"Your password is tai duan le."<<endl; 
		}
		else{
			for(int i = 0; i < len ; i ++){
				if((u[i]<='z' && u[i]>='a') || (u[i]>='A'&& u[i] <= 'Z')){
					numa++;
				}
				else if(u[i]>='0' && u[i]<='9'){
					numn++;
				} 
				else{
					if(u[i] != '.')
					nump++;
				}
			}
				//cout << numa << " " << numn << " " << nump << endl;
			if(nump){
				cout << "Your password is tai luan le."<<endl;
				continue;
			}
			else if(!numa&&numn){
				cout << "Your password needs zi mu."<<endl;
				continue;
			}
			else if(numa&&!numn){
				cout <<"Your password needs shu zi." <<endl;
				continue;
			}
			
			else if(numa&&numn){
				cout << "Your password is wan mei." <<endl;
				continue;
			}
		}
		
	}
}

　　1:这道题主要注意的是，输入的密码会有空格，所以不能简单地用string的cin 输入，得用getline输入一整行，注意格式getline(cin ,s);

2:在用getline之前还有输入的时候，一定要加getchar(),这里的getchar（）吃回车

[1082 射击比赛](https://pintia.cn/problem-sets/994805260223102976/problems/994805260990660608)

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<math.h>
using namespace std;
struct node{
	string id;
	int x,y;
	double d;
}N[10005];
int cmp(node A,node B){
	return A.d < B.d;
} 
int main(){
	int n;
	cin >> n;
	for(int i = 0 ; i < n ; i ++)
	{
		cin >>N[i].id;
		cin >> N[i].x >> N[i].y;
		N[i].d = sqrt(N[i].x*N[i].x+N[i].y*N[i].y);
		//cout << N[i].d << endl;
	}
	sort(N,N+n,cmp);
	cout << N[0].id << " " << N[n-1].id;
}

　　这道题其实就是求两点之间的距离

[1083 是否存在相等的差](https://pintia.cn/problem-sets/994805260223102976/problems/994805260780945408)

#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<string.h>
#include<map>

using namespace std;
map<int,int,greater<int>>M;
int num[10005];
int main(){
	int n;
	cin >> n;
	for(int i = 1 ; i <= n ; i ++){
		cin >> num[i];
		int cha= abs(num[i] - i);
		M[cha]++;
	}
	map<int,int>::iterator it;
	for(it = M.begin();it!=M.end();it++){
		if(it->second == 1)
		continue;
		cout << it->first << " " << it->second << endl;
	}
}

　　这道题需要让你把差从大到小的排序，并且输入相应的个数，当然仔细读题，发现个数出现一次是不需要输入的

首先让我想到STL库里的map，但是这里需要从大到小，所以用

map<int,int,greater<int>>M;来定义一个key值从大到小的Map；
map<int,int,less<int>>M; 用来定义一个key值从小到大的Map;(当然变量名随意啦~)





[1084 外观数列](https://pintia.cn/problem-sets/994805260223102976/problems/994805260583813120)

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<map>
using namespace std;
string a;
map<int,int>M;
int n,m;
void form(string &a,map<int,int>&M,int num ){
	if(num == m){
		cout << a << endl;
		return ;	
	}

	string b;
	int len = a.length();
	int ans = 1;
	for(int i = 0 ; i < len; i ++){
		if(a[i+1] == a[i]){
			++ans;
			continue;
		}else{
			M[a[i]-'0'] = ans;
			b += ( a[i]-'0' +'0' );
			b += ( ans +'0');
			ans = 1;
		}
	}
	a = b;
	b.clear();
	M.clear();
	form(a,M,num+1);
	
}
int main(){
	cin >> n >> m;
	a = n+'0';
	form(a,M,1);
}

　这道题我用的思想主要是递归~

#include<iostream>
#include<algorithm>
#include<stdio.h>
#include<string.h>
#include<map>
using namespace std;
struct node{
	double score;
	int num=0;
	string sc;
}re[100005];
int cmp(node A,node B){
	if(A.score != B.score){
		return A.score > B.score;
	}else{
		if(A.num != B.num)
		return A.num < B.num;
		else
		return A.sc < B.sc;
	}
}
map<string,node>M;
int main(){
	int n;
	cin >> n;
	for(int i = 1 ; i <= n ;i ++){
		string a,sch;
		double p;
		double pp;
		cin >> a >> p >> sch;
		transform( sch.begin(), sch.end() ,sch.begin(), ::tolower);
		//cout << sch <<endl;
		if(a[0] == 'B')
		p /=1.5;
		else if(a[0] == 'T')
		p*=1.5;
		pp = p; 
		M[sch].score+=pp;
		M[sch].num++;
		
	}
	map<string,node>::iterator it;
	int i = -1;
	for(it = M.begin(); it!=M.end(); it++){
		 re[++i].sc = it->first;
		 re[i].num = it->second.num;
		 re[i].score = (int)it->second.score;
	}
	sort(re,re+i+1,cmp);
	int rank = 0;
	int ll = 0;
	cout << M.size() << endl;
	for(int j = 0 ; j <= i ;j ++){
		if(re[j].score == re[j-1].score){
			ll++;
			cout << rank << " ";
		}else{
			cout <<(rank+ll+1) <<" ";
			rank += ll +1;
			ll = 0;
			}
			cout << re[j].sc << " " << re[j].score << " " <<re[j].num << endl;
			
		
	}
	

}

　　首先一定要注意成绩的计算，double类型，并且输出的时候需要输出整数，呢就再变为int类型

第二，排名的输入读者应该仔细思考一下，之前没怎么全面，提交一直是20，好在终于发现了错误并且改正