`#include<bits/stdc++.h> using namespace std;

const int MAXN = 1e5 + 10; struct node { int begin, end, id; }a[MAXN];

bool cmp(node a, node b) { return a.end < b.end; }

int n, ans = 0, num[MAXN], len; int main() { cin >> n; for (int i = 1; i <= n; i++) { cin >> a[i].begin >> a[i].end; a[i].id = i; }

sort(a + 1, a + n + 1, cmp);

int last = a[1].end;
ans = a[1].end - a[1].begin + 1;
num[++len] = a[1].id;

for (int i = 2; i <= n; i++)  {
	if (a[i].begin >= last) {
		ans += a[i].end - a[i].begin + 1;
		num[++len] = a[i].id;
		last = a[i].end;
	}
}

sort(num + 1, num + len + 1);

cout << ans << endl;
for (int i = 1; i <= len; i++)  {
	cout << num[i] << " ";
}

}`

我不会

我不会

#include<bits/stdc++.h>
#define int long long
const int N=1e7+10;
using namespace std;
int n,num[N],len,ans;
struct node{
	int begin,end,id;
}a[N];
bool cmp(node a1,node a2){
	return a1.end<a2.end;
}
signed main(){
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>a[i].begin>>a[i].end;
		a[i].id=i;
	}
	sort(a+1,a+n+1,cmp);
	int last=a[1].end;
	ans=a[1].end-a[1].begin+1;
	num[++len]=a[1].id;
	for(int i=2;i<=n;i++){
		if(a[i].begin>=last){
			ans+=a[i].end-a[i].begin+1;
			num[++len]=a[i].id;
			last=a[i].end;
		}
	}
	sort(num+1,num+len+1);
	cout<<ans<<endl;
	for(int i=1;i<=len;i++){
		cout<<num[i]<<" ";
	}
	return 0;
}