今天开始PTA刷题记录，文章持续更新~
对于比较难的和有坑的题会有讲解
文章目录
1001 A+B Format (20 分)
#include<iostream>
using namespace std;
int s[10];
int main(){
int a,b;
cin>>a>>b;
int sum=a+b;
bool A=0;
if(sum<0){
sum*=(-1);
A=1;
}
if(sum==0) cout<<0;
int n=0;
while(sum){
s[++n]=sum%10;
sum/=10;
}
if(A) cout<<"-";
for(int i=n;i;i--){
cout<<s[i];
if(i==n-n%3+1&&n>=4) cout<<",";
if((i-(n-n%3+1))%3==0&&i/4>0&&i!=n-n%3+1) cout<<",";
}
return 0;
}
1002 A+B for Polynomials (25 分)
#include<iostream>
#include<stdio.h>
using namespace std;
double ans[1010]={0};
bool v[10100]={false};
int main(){
int k1,k2;
cin>>k1;
int a;
double k;
int num=0;
for(int i=0;i<k1;i++){
cin>>a>>k;
if(!v[a]&&k!=0.0){v[a]=1;num++;}
ans[a]+=k;
}
cin>>k2;
for(int i=0;i<k2;i++){
cin>>a>>k;
if(!v[a]&&k!=0.0){v[a]=1;num++;}
ans[a]+=k;
}
// cout<<v[0]<<endl;
cout<<num;
for(int i=1000;i>=0;i--){
if(ans[i]!=0 ) printf(" %d %.1f", i,ans[i]);
}
return 0;
}
1005 Spell It Right (20 分)
#include<iostream>
using namespace std;
void Eng(int x){
if(x==0) cout<<"zero";
else if(x==1) cout<<"one";
else if(x==2) cout<<"two";
else if(x==3) cout<<"three";
else if(x==4) cout<<"four";
else if(x==5) cout<<"five";
else if(x==6) cout<<"six";
else if(x==7) cout<<"seven";
else if(x==8) cout<<"eight";
else cout<<"nine";
}
int main(){
string s;
cin>>s;
int n=s.size();
int sum=0;
for(int i=0;i<n;i++){
sum+=(int)(s[i]-'0');
}
int mm=0,summ=sum;
while(summ){summ/=10;mm++;}
int m=1;
for(int i=1;i<mm;i++) m*=10;
//cout<<sum<<" "<<m<<endl;
while(sum||m){
int k=sum/m;
Eng(k);
sum=sum%m;
m/=10;
if(m) cout<<" ";
}
return 0;
}
1006 Sign In and Sign Out (25 分)
#include <iostream>
using namespace std;
int main(){
string open_id,open_time;
string close_id,close_time;
int m;
cin >> m;
for(int i = 0;i < m ; i ++){
string id, in_time , out_time;
cin >> id >> in_time >> out_time;
if(!i || open_time > in_time) {
open_time = in_time;
open_id = id;
}
if(!i || close_time < out_time) {
close_time = out_time;
close_id = id;
}
}
cout << open_id << ' ' << close_id;
}
1007 Maximum Subsequence Sum (25 分)(最大子序列和）
//最大子序列和
#include<iostream>
using namespace std;
int a[100086];
int main(){
int n;
cin>>n;
int m=0;
for(int i=0;i<n;i++){
cin>>a[i];
if(a[i]<0) m++;
}
if(m==n){
cout<<0<<" "<<a[0]<<" "<<a[n-1];
return 0;
}
long long maxx=a[0],l=a[0],r=a[0];
for(int i=0;i<n;i++){
int s=0;
for(int j=i;j<n;j++){
s+=a[j];
if(s>maxx){
maxx=s;
l=a[i];
r=a[j];
}
}
}
cout<<maxx<<" "<<l<<" "<<r<<endl;
return 0;
}
1008 Elevator (20 分)
#include<iostream>
using namespace std;
int a[10086];
int main(){
int n;
cin>>n;
long long sum=n*5;
for(int i=0;i<n;i++){
cin>>a[i];
if(!i) sum+=6*a[i];
else{
if(a[i]>a[i-1]) sum+=(a[i]-a[i-1])*6;
else if(a[i]==a[i-1]) sum+=0;
else sum+=(a[i-1]-a[i])*4;
}
}
cout<<sum<<endl;
}
1009 Product of Polynomials (25 分)
#include<iostream>
using namespace std;
int ae[10086],be[10086];
double ac[10086],bc[10086];
double ans[10086];
int main(){
int n,m;
cin>>n;
for(int i=0;i<n;i++) cin>>ae[i]>>ac[i];
cin>>m;
for(int i=0;i<m;i++) cin>>be[i]>>bc[i];
for(int i=0;i<m;i++){
for(int j=0;j<n;j++){
int sum=0;
sum=ae[j]+be[i];
ans[sum]+=ac[j]*bc[i];
// cout<<sum<<ac[j]*be[i]<<" "<<ac[j]<<" "<<bc[i]<<endl;
}
}
int k=0;
for(int i=2000;i>=0;i--){
if(ans[i]!=0.0) k++;
}
cout<<k;
for(int i=2000;i>=0;i--){
if(ans[i]!=0.0) printf(" %d %.1lf",i,ans[i]);
}
return 0;
}
1010 Radix (25 分)（大坑）
#include<iostream>
using namespace std;
#define int long long int
int jinshi(string s,int k){
int sum=0,m=1;
for(int i=s.size()-1;i>=0;i--){
if(isdigit(s[i])){sum+=(int)(s[i]-'0')*m;m*=k;}
else{sum+=(int)(s[i]-'a'+10)*m;m*=k;}
}
return sum;
}
int find(int l,int r,int n,string s){
int m;
while(l<=r){
int mid=(l+r)/2;
m=jinshi(s,mid);
//cout<<m<<" "<<n<<" "<<mid<<" "<<s<<endl;
if(m==n) return mid;
if(m>n||m<0) r=mid-1;
else l=mid+1;
}
return -1;
}
signed main(){
string n1,n2;
int t,r;
cin>>n1>>n2>>t>>r;
if(n1==n2){cout<<r;return 0;}
if(t==2) swap(n1,n2);
int a=jinshi(n1,r);
int minn=0,maxx;
for(int i=0;i<n2.size();i++){
if(isdigit(n2[i])){
if((int)(n2[i]-'0'+1)>minn) minn=(int)(n2[i]-'0'+1);
}else{
if((int)(n2[i]-'a'+1)>minn) minn=(int)(n2[i]-'a'+11);
//cout<<"z"<<endl;
}
}
maxx=max(minn,a);
//cout<<maxx<<" "<<minn<<endl;
int ans=find(minn,maxx,a,n2);
if(ans==-1) cout<<"Impossible";
else cout<<ans;
}
1011 World Cup Betting (20 分)
#include<iostream>
#include<algorithm>
using namespace std;
struct sz{
int n;
double m;
}a[4];
int cmp(sz x,sz y){
return x.m>y.m;
}
int main(){
double sum=1;
for(int i=0;i<3;i++){
cin>>a[0].m>>a[1].m>>a[2].m;
a[0].n=1,a[1].n=2,a[2].n=3;
sort(a,a+3,cmp);
sum*=a[0].m;
if(a[0].n==1) cout<<"W ";
else if(a[0].n==2) cout<<"T ";
else cout<<"L ";
}
sum=(sum*0.65-1)*2;
printf("%.2lf",sum);
return 0;
}
1015 Reversible Primes (20 分)
一直WA了第二组数据，结果是因为，0，1，不是素数。。。
#include<iostream>
#include<cstring>
#include<math.h>
using namespace std;
const int N=10010000;
int str[N],str_n;
void jinzhi(int k,int x){
while(x){
int m=x%k;
str[str_n++]=m;
x/=k;
}
return;
}
int zhuan(int k){
int sum=0,m=1;
for(int i=str_n-1;i>=0;i--){
sum+=str[i]*m;
m*=k;
}
return sum;
}
bool pri(int x){
//0,1不算质数
if(x==0||x==1) return false;
for(int i=2;i<=sqrt(x);i++){
if(x%i==0) return false;
}
return true;
}
int main(){
int n,d;
while(cin>>n){
memset(str,0,sizeof str);
str_n=0;
if(n<0) return 0;
cin>>d;
if(!pri(n)){cout<<"No"<<endl;continue;}
jinzhi(d,n);
int m=zhuan(d);
//cout<<m<<endl;
if(!pri(m)){cout<<"No"<<endl;continue;}
else cout<<"Yes"<<endl;
}
return 0;
}