code233520 @ 2024-06-29 16:51:25
用的是区间合并，如果看完回答十分感谢！
#include <bits/stdc++.h>
using namespace std;
// l表示马路的长度，n表示区域的段数，st,ed表开始结束
int l, n, st, ed;
typedef vector<pair<int, int>> arr;
arr segs;
int func(arr segs)
{
arr temp;
int ans;
sort(segs.begin(), segs.end());
int st = -1e9, ed = -1e9;
for (auto seg : segs)
{
if (ed < seg.first)
{
if (ed != -1e9)
temp.push_back({st, ed});
st = seg.first;
ed = seg.second;
}
else
ed = max(ed, seg.second);
}
if (ed != -1e9)
temp.push_back({st, ed});
for (auto seg : temp)
{
ans += seg.second - seg.first + 1;
}
return ans;
}
int main()
{
cin >> l >> n;
for (int i = 1; i <= n; i++)
{
cin >> st >> ed;
segs.push_back({st, ed});
}
int ans = l + 1 - func(segs);
printf("%d", ans);
return 0;
}by zkszks @ 2024-06-29 17:01:22
啊会不会写错了呢
by Demfoqzil_Fly @ 2024-07-05 20:34:33
试试这个：
#include<bits/stdc++.h>
using namespace std;
int a[10005];
int main () {
int l, m, cnt=0;
cin>>l>>m;
for(int i=0; i<=l; i++) a[i]=1;
for(int i=1; i<=m; i++){
int x, y;
cin>>x>>y;
for(int j=x; j<=y; j++)
a[j]=0;
}
for(int i=0; i<=l; i++){
if(a[i]==1){
cnt++;
}
}
cout<<cnt;
return 0;
}
by yuxiang_wang @ 2024-07-06 15:23:40
#include<bits/stdc++.h>
using namespace std;
int main(){
int l,m,cnt=0;
cin>>l>>m;
bool tree[100010]={};
for(int i=0;i<m;i++){
int a,b;
cin>>a>>b;
for(int j=a;j<=b;j++)tree[j]=1;
}
for(int i=0;i<=l;i++)if(!tree[i])cnt++;
cout<<cnt;
return 0;
}