考试的时候一直不对,求改
//
// Created by 55062 on 2023/12/17.
//
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
struct node{
ll l,r,zx,shu,zt;
}ans[300010];
ll n,cnt,x,sum,l=1,abc=0x3f3f3f3f,abb;
char a[300010];
int main(){
cin>>n;
for(int i=1;i<=n;i++) cin>>a[i];
a[n+1]='0';
for(int i=1;i<=n;i++)
if(a[i]=='1') sum++;
for(int i=1;i<=n+1;i++) {
if (a[i] == '1') x++;
if (a[i] == '1' && a[i + 1] == '0') {
ans[++cnt].shu = x;
ans[cnt].l=l;
ans[cnt].r=i;
l=i+1;
x=0;
}if(a[i]=='0') l++;
}/*
for(int i=1;i<=cnt;i++)
if(ans[i].shu==1||(ans[i].shu%2==0&&ans[i].l!=1&&ans[i].r!=n)){
cout<<sum;
exit(0);
}*/
for(int i=1;i<=cnt;i++){
if(ans[i].shu%2==0) ans[i].zx=ans[i].shu/2;
else ans[i].zx=(ans[i].shu-1)/2;
}for(int i=1;i<=cnt;i++)
if(ans[i].zx!=0) abc=min(abc,ans[i].zx);
for(int i=1;i<=cnt;i++){
if(ans[i].zx==abc) ans[i].zt=1;
else if(ans[i].l!=1&&ans[i].r!=cnt){
ll l=ans[i].l+abc*2,r=ans[i].r-abc*2;
ans[i].zt=2;
ll x=r-l-1;
if(x>0){
ll h=abc*2+1;
ans[i].zt+=x/h;
if(x%h!=0) ans[i].zt++;
}
}else{
ll h=abc*2+1;
ans[i].zt=ans[i].shu/h;
if(ans[i].zt%h!=0) ans[i].zt++;
}
}for(int i=1;i<=cnt;i++) abb+=ans[i].zt;
cout<<abb;
return 0;
}