hiho第152周，离散化记笔记记笔记

感觉自己用node+map的存数据方案有点烦，
不过还没想到什么骚操作简化，用二进制的话也是换汤不换药，
一开始node里面全是bool导致A集合里重叠左端点的区间只算了一次，
60分无限WA，改成int，我真傻，真的

#include <map>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long LL;
const LL N = 1e7 + 7;

struct node{
    int al, ar, bl, br;
    node(){}
    node(int x, int y, int z, int w):al(x),ar(y),bl(z),br(w){}
    node add(node b){return node(al+b.al, ar+b.ar, bl+b.bl, br+b.br);}
}nodes[N];

LL n, m, a[N];
map <LL,LL> mp;

int main()
{
    //freopen("in.txt", "r", stdin);
    scanf("%lld%lld", &n, &m);
    LL l, r, top = 0;
    memset(nodes, 0, sizeof(nodes));

    for (LL i = 1; i <= n; i++){
        scanf("%lld%lld", &l, &r);
        if (!mp[l]) mp[l] = ++top;
        nodes[mp[l]] = nodes[mp[l]].add(node(1,0,0,0));
        if (!mp[r]) mp[r] = ++top;
        nodes[mp[r]] = nodes[mp[r]].add(node(0,1,0,0));
        a[i*2 - 1] = l;
        a[i*2] = r;
    }
    for (LL i = 1; i <= m; i++){
        scanf("%lld%lld", &l, &r);
        if (!mp[l]) mp[l] = ++top;
        nodes[mp[l]] = nodes[mp[l]].add(node(0,0,1,0));
        if (!mp[r]) mp[r] = ++top;
        nodes[mp[r]] = nodes[mp[r]].add(node(0,0,0,1));
        a[n*2 + i*2 - 1] = l;
        a[n*2 + i*2] = r;
    }

    sort(a + 1, a + 2*n+2*m+1 );
    // top == cnt
    LL cnt = unique(a+1, a+n*2+m*2+1) - (a+1);
    LL cntA = 0, cntB = 0, ans = 0;

    for (LL i = 1; i < cnt; i++){
        node t = nodes[mp[a[i]]];
        cntA += t.al - t.ar;
        cntB += t.bl - t.br;
        //printf("%lld %lld
", cntA, cntB);
        if (cntA > 0 && cntB == 0){
            ans += a[i+1] - a[i];
        }
    }
    printf("%lld
", ans);
    return 0;
}

几秒后的更新：
丢到map，不去重直接排序
不仅丢掉了wa点，还扔掉了很多冗余过程

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long LL;
const LL N = 1e7 + 7;
struct node{
    int index, al, ar, bl, br;
    node(){}
    node(int in, int x, int y, int z, int w):index(in),al(x),ar(y),bl(z),br(w){}
    bool operator <(const node& b)const{return index < b.index;}
}nodes[N];
LL n, m;

int main()
{
    //freopen("in.txt", "r", stdin);
    scanf("%lld%lld", &n, &m);
    LL l, r, top = 0;
    memset(nodes, 0, sizeof(nodes));

    for (LL i = 1; i <= n; i++){
        scanf("%lld%lld", &l, &r);
        nodes[++top] = node(l,1,0,0,0);
        nodes[++top] = node(r,0,1,0,0);
    }
    for (LL i = 1; i <= m; i++){
        scanf("%lld%lld", &l, &r);
        nodes[++top] = node(l,0,0,1,0);
        nodes[++top] = node(r,0,0,0,1);
    }

    sort(nodes + 1, nodes + top +1 );
    LL cntA = 0, cntB = 0, ans = 0;

    for (LL i = 1; i < top; i++){
        node t = nodes[i];
        cntA += t.al - t.ar;
        cntB += t.bl - t.br;
        //printf("%lld %lld
", cntA, cntB);
        if (cntA > 0 && cntB == 0){
            ans += nodes[i+1].index - t.index;
        }
    }
    printf("%lld
", ans);
    return 0;
}