提供两种思路
一种线段树区间更新
另一种用map维护连续的区间，也是题解的思路
第二种很难写(我太渣，看了别人的代码，发现自己写的太烦了)

#include<iostream>

#include<map>

#include<iostream>

#include<cstring>

#include<cstdio>

#include<set>

#include<vector>

#include<queue>

#include<stack>

#include<cmath>

#include<algorithm>

using namespace std;

typedef long long ll;

const int INF = 0x3f3f3f3f;

const int N = 6e5+5;

#define MS(x,y) memset(x,y,sizeof(x))

#define MP(x, y) make_pair(x, y)

#define lson l, m, rt<<1

#define rson m+1, r, rt<<1|1

int main() {

    int n, q;

    while(~scanf("%d %d", &n, &q)) {

        map<int, int> mp;

        mp[-1] = -1;

        mp[1] = n;

        mp[n+1] = INF;

        int ans = n;

        while(q --) {

            int l, r, k; 

            scanf("%d %d %d", &l, &r, &k);

            int tt = r;

            if(k == 2 && r != n) tt = r+1;

            auto it = mp.upper_bound(l);

            auto it2 = mp.upper_bound(tt);

            it --; it2 --;

            int head1 = it -> first;  int len1 = it -> second;

            int head2 = it2 -> first;  int len2 = it2 -> second;

            while(1){

                int flag = 0;

                if(it == it2) flag = 1;

                ans -= it->second;

                auto tmp = it;

            //  if(it->first == n+1) while(1);

                it ++;

        //      printf("erase: %d\n", tmp->first);

                mp.erase(tmp);

                if(flag) break;

            }

        //for(auto i = mp.begin(); i != mp.end(); ++i) printf("%d:%d ", i->first, i->second); printf("\n");

        //  printf("%d %d %d %d %d %d\n", head1, len1, head2, len2, l, r);

            if(k == 1) {

                if(head1 + len1 - 1 >= l && l!=head1) {

                    mp[head1] = l - head1;

                    ans += l - head1;

                } else if(l != head1){

                    mp[head1] = len1;

                    ans += len1;

                }

                if(head2 + len2 - 1 > r) {

                    mp[r+1] = head2 + len2 - 1 - r;

                    ans += head2 + len2 - 1 - r;

                }

            } else {

                int L = l; int R = max(r, head2 + len2 -1);

                if(head1 + len1 < l) {

                    mp[head1] = len1;

                    ans += len1;

                }else L = head1;

                mp[L] = R-L+1;

                ans += R-L+1;

            }

    //      for(auto i = mp.begin(); i != mp.end(); ++i) printf("%d:%d ", i->first, i->second); printf("\n");

            printf("%d\n", ans);

        }

    }

    return 0;

}

#include<iostream>

#include<map>

#include<iostream>

#include<cstring>

#include<cstdio>

#include<set>

#include<vector>

#include<queue>

#include<stack>

#include<cmath>

#include<algorithm>

using namespace std;

typedef long long ll;

const int INF = 0x3f3f3f3f;

const int N = 6e5+5;

#define MS(x,y) memset(x,y,sizeof(x))

#define MP(x, y) make_pair(x, y)

#define lson l, m, rt<<1

#define rson m+1, r, rt<<1|1

int Q[N][3];

int has[N * 2]; int cnt;

int sum[N << 2];

int lazy[N << 2];

void build(int l, int r, int rt) {

    lazy[rt] = 0;

    sum[rt] = has[r] - has[l-1];

    if(l == r) {

        return;

    }

    int m = (l + r) >> 1;

    build(lson); build(rson);

}

void update(int ty, int L, int R, int l, int r, int rt) {

    //printf("%d %d\n", l, r);

    if(L <= has[l-1]+1 && has[r] <= R) {

        lazy[rt] = ty == 1? -1 : 1;

        sum[rt] = ty == 1? 0 : has[r] - has[l-1];

        return;

    }

    int m = (l + r) >> 1;

    if(lazy[rt] == 1) {

        lazy[rt<<1] = 1; sum[rt<<1] = has[m] - has[l-1];

        lazy[rt<<1|1] = 1; sum[rt<<1|1] = has[r] - has[m];

        lazy[rt] = 0;

    } else if(lazy[rt] == -1){

        lazy[rt<<1] = -1; sum[rt<<1] = 0;

        lazy[rt<<1|1] = -1; sum[rt<<1|1] = 0;

        lazy[rt] = 0;

    }

    if(L <= has[m-1]+1) update(ty, L, R, lson);

    if(R > has[m])  update(ty, L, R, rson);

    sum[rt] = sum[rt<<1] + sum[rt<<1|1];

}

void debug(int l, int r, int rt) {

    printf("%d %d %d\n", l, r, sum[rt]);

    if(l == r) return;

    int m = (l + r) >> 1;

    debug(lson);

    debug(rson);

}

int main() {

    int n;

    while(~scanf("%d", &n)) {

        cnt = 0;

        int q; scanf("%d", &q);

        for(int i = 0; i < q; ++i) {

            scanf("%d %d %d", &Q[i][0], &Q[i][1], &Q[i][2]);

            has[cnt ++] = Q[i][0] - 1;

            has[cnt ++] = Q[i][1];

        }

        has[cnt ++] = 0;

        has[cnt ++] = n;

        sort(has, has+cnt);

        cnt = unique(has, has + cnt) - has;

//      for(int i = 0; i < cnt; ++i) printf("%d ", has[i]); printf("\n");

        build(1, cnt-1, 1);

    //` debug(1, cnt-1, 1);

        for(int i = 0; i < q; ++i) {

            update(Q[i][2], Q[i][0], Q[i][1], 1, cnt-1, 1);

            printf("%d\n", sum[1]);

    //      debug(1, cnt-1, 1);

        }

    }

    return 0;

}