A
题目链接：http://codeforces.com/contest/1335
思路：简单的推理：
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
int t;
scanf("%d",&t);
while(t--)
{
ll a;
scanf("%lld",&a);
if(a<=2)
printf("0
");
else if(a%2==0)
printf("%lld
",a/2-1);
else
printf("%lld
",a/2);
}
return 0;
}
B
思路：逐位考虑，保持循环即可，字符串拥有循环节
//-------------------------------------------------
//Created by HanJinyu
//Created Time :三 4/15 23:10:31 2020
//File Name :cf3B.cpp
//-------------------------------------------------
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <list>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#define long long ll
#define double db
#define maxn 200005
using namespace std;
void disp(int a,int b)
{
for(int i=1;i<=a/b;i++)
{
for(int j=0;j<b;j++)
{
printf("%c",97+j);
}
}
for(int i=0;i<a%b;i++)
printf("%c",97+i);
}
int main()
{
//freopen("in.txt","r",stdin);
//freopen("out.txt","w",stdout);
int T;
scanf("%d",&T);
while(T--)
{
int n,a,b;
scanf("%d%d%d",&n,&a,&b);
int num=n/a;
int num1=n%a;
for(int k=0;k<num;k++)
disp(a,b);
int ops=0;
for(int t=a%b;t<a%b+num1;t++)
{
if(t>=b)
{
break;
}
else{
ops++;
printf("%c",97+t);
}
}
if(num1-ops<=b){
for(int i=0;i<(num1-ops);i++)
printf("%c",97+i);
}
else
disp(num1-ops,b);
printf("
");
}
return 0;
}
c
思路：比较数字出现的最多次数那个数字的次数和数组不同的个数，输出最小的即可
//
// Created by H on 2020/4/13.
//
#include<bits/stdc++.h>
using namespace std;
int main()
{
int t;
scanf("%d",&t);
while(t--)
{
map<int,int>ap;
int n;
scanf("%d",&n);
int mm;
for(int i=0;i<n;i++)
{
scanf("%d",&mm);
ap[mm]++;
}
int cishu=0;
for(auto v:ap)
{
cishu=max(cishu,v.second);
}
if(ap.size()==cishu)
cout<<cishu-1<<endl;
if(ap.size()>cishu)
cout<<cishu<<endl;
if(ap.size()<cishu)
cout<<ap.size()<<endl;
}
return 0;
}
D
思路：数独，只要任意将一个数变成另外一个数即可
//-------------------------------------------------
//Created by HanJinyu
//Created Time :四 4/16 13:35:36 2020
//File Name :shudu.cpp
//-------------------------------------------------
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <list>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <time.h>
#define long long ll
#define double db
#define maxn 200005
using namespace std;
int main()
{
//freopen("in.txt","r",stdin);
//freopen("out.txt","w",stdout);
int t;
scanf("%d",&t);
while(t--)
{
char ch[10][10];
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
cin>>ch[i][j];
if(ch[i][j]=='1')
ch[i][j]='2';
}
}
for(int i=0;i<9;i++)
{
for(int j=0;j<9;j++)
{
cout<<ch[i][j];
}
cout<<endl;
}
}
return 0;
}