Charles_koyi @ 2024-08-20 12:51:47

#include<bits/stdc++.h>
using namespace std;
int l,m;
struct d{
    int u,v;
}doge[101];
bool cmp(d x,d y)
{
    if(x.u>y.u)
    {
        return x.u<y.u;
    }
}
int main()
{
    cin>>l>>m;
    l++;
    for(int i=0;i<m;i++)
    {
        cin>>doge[i].u>>doge[i].v;
    }
    sort(doge,doge+m,cmp);
    for(int i=1;i<m;i++)
    {
        if(doge[i].u<doge[i-1].v)//去重合部分
        {
            doge[i].u=doge[i-1].v+1;
        }
        if(doge[i].v<doge[i].u)//如果全重合就删去
        {
            doge[i].u=0;
            doge[i].v=0;
        }
    }
    for(int i=0;i<m;i++)
    {
        if(doge[i].u==0 and doge[i].v==0)
        {
            continue;
        }
        l=l-(doge[i].v-doge[i].u+1);
    }
    cout<<l;
    return 0;
}

by Lisuyang @ 2024-08-20 13:21:58

#include <iostream>
using namespace std;
int a[10006];
int main(){
    int L, M, x, y, sum = 0;
    scanf("%d%d", &L, &M);
    for(int i = 1; i <= M; ++ i){
        scanf("%d%d", &x, &y);
        for(int j = x; j <= y; ++ j){
            if(a[j] == 0)
                a[j] = 1;
        }
    }
    for(int i = 0; i <= L; ++ i){
        if(a[i] == 0)
            ++ sum;
    }
    printf("%d", sum);
    return 0;
}

by ycy130114 @ 2024-08-21 11:30:28

\textcolor{red}{求关}

#include<bits/stdc++.h>
using namespace std;
int a[100010],ans;
int main()
{
    memset(a,0,sizeof(a));
    int l,m;
    cin>>l>>m;
    for(int i=0;i<=l;i++)
        a[i]=0;
    for(int i=1;i<=m;i++)
    {
        int q,p;
        cin>>q>>p;
        for(int j=q;j<=p;j++)
        {
            if(a[j]==0)
            {
                a[j]=1;
            }
        }
    }
    for(int i=0;i<=l;i++)
    {
        if(a[i]==0)
        {
            ans++;
        }
    }
    cout<<ans;
    return 0;
}

\textcolor{red}{求关}

by wangyanxi @ 2024-08-21 23:13:26

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
bool tree[10005];
int main(){

    int l, m;
    cin >> l >> m;
    memset(tree,true,sizeof(tree));

    for (int i = 1;i <= M;i++)
    {
        int start,end;
        cin >> start >> end; 
        //把范围内的数去掉
        for (int j = start;j <= end;j++) tree[j] = false;
    }
    int cnt = 0;
    for (int i = 0;i <= L;i++) //必须从0开始
        cnt += tree[i];
    cout << cnt;
    return 0;
}

需要注意的是最后一个循环

必须从零开始