2018西北工业大学机试试题

 

#include<iostream>
using namespace std;
int main(){
	
	int a,b;
	int n;
	cin>>n;
	for(int i = 0;i < n;i++){
		cin>>a>>b;
		cout<<a*b<<endl;
	}
	
	return 0;
} 

 

#include<iostream>
using namespace std;
int main(){
	
	int n,m;
	cin>>n;
	for(int i = 0;i < n;i++){
		cin>>m;
		int cnt = 1;
		for(int j = 1;j <= m;j++){
			cnt *= j;
		}
		cout<<cnt<<endl;
	}
	
	return 0;
} 

 

#include<iostream>
using namespace std;
int main(){
	//n!/((n-m)!*m!) 可以进行约分 
	long long n,m;
	cin>>n>>m;
	long long cnt1 = 1,cnt2 = 1;
	long long cnt = 0;
	for(long long i = n;i >= 1&&cnt < m;i--,cnt++) {
		cnt1 *= i;
	}
	
	for(long long i = 1;i<=m;i++) {
		cnt2 *= i;
	}
	cout<<cnt1/cnt2<<endl;
	return 0;
} 

 

#include<iostream>
#include<algorithm>
#include<vector> 
using namespace std;
int main(){
	
	int n,m,a;
	cin>>n>>m;
	for(int i = 0;i < n;i++){
		vector<int>v;
		for(int j = 0;j < m;j++){
			cin>>a;
			v.push_back(a);
		}
		sort(v.begin(),v.end());
		for(int j = 0;j < m;j++){
			if(j == m-1){
				cout<<v[j]<<endl;;
			}else{
				cout<<v[j]<<" ";
			}
		}
	}
	return 0;
} 

 

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
	
	int n;
	cin>>n;
	string s;
	getchar();
	for(int i = 0;i < n;i++){
		getline(cin,s);
		reverse(s.begin(),s.end());
		cout<<s<<endl;
	}
	return 0;
} 

 

#include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
	
	int n,j = 0;
	cin>>n;
	string s,s1;
	getchar();
	for(int i = 0;i < n;i++){
		getline(cin,s);
		s1 = s;
		reverse(s.begin(),s.end());
		for(j = 0;j < s.length()&&s[j] == s1[j];j++);
		if(j == s.length()){
			cout<<"yes"<<endl;
		}else{
			cout<<"no"<<endl;
		}
	}
	return 0;
} 

 

#include<iostream>
#include<string>
#include<stack>
using namespace std;
int a[300][300]={0};
int main(){
//	freopen("input.txt","r",stdin);
	int n;
	a['{']['}'] = 1;
	a['['][']'] = 1;
	a['('][')'] = 1;
	string str;
	cin>>n;
	for(int i = 0;i < n;i++){
		cin>>str;
		cout<<str<<endl;
		stack<char>s;
		int j;
		bool flag = true;
		for(j = 0;j < str.length();j++){
			if(str[j] == '{'||str[j] == '['||str[j] == '('){
				s.push(str[j]);//左边负号 
			}else if(str[j] == '}'||str[j] == ']'||str[j] == ')'){
				//右边符号 
				if(s.size() == 0){//栈为空，不匹配 
					cout<<"no"<<endl;
					flag = false;
					break;
				}
				if(a[s.top()][str[j]]==1){//匹配，出栈 
					s.pop();
				}else{//不匹配 
					cout<<"no"<<endl;
					flag = false;
					break;
				}
			}
		}
		if(flag&&s.size()==0){//若匹配，则栈为空，并且flag为true 
			cout<<"yes"<<endl;
		}
		if(flag&&s.size()>0){//若匹配，则栈不为空或者flag为false
			cout<<"no"<<endl;
		}
	}
	return 0;
}