60分求助

#include<bits/stdc++.h>
using namespace std;
long long m[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
long long z[100010],n,ans;
long long sum1,sum2,sum,a1,a2,b1,b2,c1,c2,d1,d2,e1,e2;
int main()
{
    cin>>n;
    for (int i=1;i<=n;i++)
    {
        cin>>z[i];
    }
    sort(z+1,z+n+1);
    string x,y;
    cin>>x>>y;
    a1=(x[0]-'0')*1000+(x[1]-'0')*100+(x[2]-'0')*10+(x[3]-'0');
    b1=(x[5]-'0')*10+(x[6]-'0');
    c1=(x[8]-'0')*10+(x[9]-'0');
    d1=(x[11]-'0')*10+(x[12]-'0');
    e1=(x[14]-'0')*10+(x[15]-'0');
    for (int i=0;i<=a1;i++)
    {
        if ((i%4==0&&i%100!=0)||i%400==0)
        m[2]=29;
        else
        m[2]=28;
        if (i<a1)
        {
            sum1+=(365+(m[2]-28))*24*60;
        }
        else
        {
            for (int i=1;i<=b1;i++)
            {
                if (i<b1)
                {
                    sum1+=m[i]*24*60;
                }
                else
                {
                    sum1+=(c1-1)*24*60;
                    sum1+=(d1-1)*60;
                    sum1+=e1;
                }
            }
        }
    }
    a2=(y[0]-'0')*1000+(y[1]-'0')*100+(y[2]-'0')*10+(y[3]-'0');
    b2=(y[5]-'0')*10+(y[6]-'0');
    c2=(y[8]-'0')*10+(y[9]-'0');
    d2=(y[11]-'0')*10+(y[12]-'0');
    e2=(y[14]-'0')*10+(y[15]-'0');
    for (int i=0;i<=a2;i++)
    {
        if ((i%4==0&&i%100!=0)||i%400==0)
        m[2]=29;
        else
        m[2]=28;
        if (i<a1)
        {
            sum2+=(365+(m[2]-28))*24*60;
        }
        else
        {
            for (int j=1;j<=b2;j++)
            {
                if (j<b2)
                {
                    sum2+=m[j]*24*60;
                }
                else
                {
                    sum2+=(c2-1)*24*60;
                    sum2+=(d2-1)*60;
                    sum2+=e2;
                }
            }
        }
    }
    sum=sum2-sum1;
    for (int i=1;i<=n;i++)
    {
        if (sum>=z[i])
        {
            ans++;
            sum-=z[i];
        }
        else
        {
            break;
        }
    }
    cout<<ans;
}