[Greedy] [summary] exercises

uva1149

Ideas: sort, from the largest to start, from the smallest start traversal can be put together to put (the operation here is set to -1), and then break, can not be put together on their own account for a note to find the smallest to exclude - case 1.

#include <iostream>
#include <queue>
#include <algorithm>
using namespace std;

const int maxn=100000+10;
int t,n,bin;
int a[maxn];

int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        int ans=0;
        cin>>n>>bin;
        for(int i=0;i<n;++i)
            cin>>a[i];
        sort(a,a+n);
        for(int i=n-1;a[i]!=-1;--i)
        {
            if(a[i]<=bin)
            {
                ans++;
                for(int j=0;j<n;j++)
                {
                    if(a[j]==-1)continue;
                    else if(a[i]+a[j]<=bin){a[j]=-1;break;}
                    else break;
                }
            }
        }
        cout<<ans<<endl;
        if(t)cout<<endl;
    }
    return 0;
}

uva12545

#include <iostream>
#include <queue>
#include <algorithm>
#include <cstdio>
#include <cstring>
using namespace std;

const int maxn=105;
char s[maxn],t[maxn];

int main()
{
    int kase=0;
    int T;
    cin>>T;
    while(T--)
    {
        cin>>s>>t;
        printf("Case %d: ",++kase);
        int len=strlen(s);
        int snum=0,tnum=0,qnum=0,ans=0;
        for(int i=0;i<len;i++)
        {
            if(s[i]=='0')snum++;
            if(t[i]=='0')tnum++;
            if(s[i]=='?'){qnum++;ans++;}
            if(t[i]=='0'&&s[i]=='?')
            {
                s[i]=='0';
                snum++;
                qnum--;
            }
        }
        if(snum+qnum<tnum){printf("-1\n");continue;}
        int sub=tnum-snum;
        int s0=0;
        for(int i=0;i<len;i++)
        {
            if(s[i]=='0'&&t[i]=='1')s0++;
        }
        if(sub>0)s0+=sub;
        ans+=s0;
        cout<<ans<<endl;
    }
    return 0;
}