暑假集训cf50练之15

Posted 2020-09-29 walfy

Codeforces Round #370 (Div. 2)

A水，直接看样例找规律，数组开小导致wa了一发。。。

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define ull unsigned long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")

using namespace std;

const double g=10.0,eps=1e-12;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;

ll a[N];
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin>>n;
    for(int i=0;i<n;i++)cin>>a[i];
    a[n]=0;
    for(int i=0;i<n;i++)
    {
        cout<<a[i]+a[i+1]<<" ";
    }
    cout<<endl;
    return 0;
}
/*********************

*********************/

A

B记录udlr的数目，求解的过程出了问题wa了两发。。。

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define ull unsigned long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")

using namespace std;

const double g=10.0,eps=1e-12;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    string s;
    cin>>s;
    if(s.size()&1)
    {
        cout<<-1<<endl;
        return 0;
    }
    int u=0,d=0,l=0,r=0;
    for(int i=0;i<s.size();i++)
    {
        if(s[i]==‘U‘)u++;
        else if(s[i]==‘D‘)d++;
        else if(s[i]==‘L‘)l++;
        else if(s[i]==‘R‘)r++;
    }
    int ans=0;
    if((u+d)%2==1)
    {
        ans++;
        ans+=abs(u-d)/2;
        ans+=abs(l-r)/2;
    }
    else
    {
        ans+=abs(u-d)/2;
        ans+=abs(l-r)/2;
    }
    cout<<ans<<endl;
    return 0;
}
/*********************
UUUU
*********************/

B

C很水，直接暴力1a

#include<map>
#include<set>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cassert>
#include<iomanip>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define ull unsigned long long
#define mod 1000000007
#define ls l,m,rt<<1
#define rs m+1,r,rt<<1|1
#pragma comment(linker, "/STACK:1024000000,1024000000")

using namespace std;

const double g=10.0,eps=1e-12;
const int N=100000+10,maxn=500+100,inf=0x3f3f3f;

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    int a,b;
    cin>>a>>b;
    int x=b,y=b,z=b,k=0;
    while(x<a&&y<a&&z<a){
        int te=x+y+z-min(x,min(y,z));
        if(x==min(x,min(y,z)))x=te-1;
        else if(y==min(x,min(y,z)))y=te-1;
        else z=te-1;
        k++;
     //   cout<<x<<" "<<y<<" "<<z<<endl;
    }
    cout<<k+2<<endl;
    return 0;
}
/*********************

*********************/

C