思路：

分块，复杂度有点玄学，和普通分块不同的是在这个块被一次染色的时候暴力染整个块。

代码：

#pragma GCC optimize(2)#pragma GCC optimize(3)#pragma GCC optimize(4)#include
     
      using namespace std;#define fi first#define se second#define pi acos(-1.0)#define LL long long//#define mp make_pair#define pb push_back#define ls rt<<1, l, m#define rs rt<<1|1, m+1, r#define ULL unsigned LL#define pll pair
      
       #define pii pair
       
        #define piii pair
        
         #define mem(a, b) memset(a, b, sizeof(a))#define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);#define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout);//headconst int N = 1e5 + 5, M = 410;int a[N], lazy[M], bl[N], blo, n;LL v[N], bv[M], sm[M];void push_down(int x) {    for (int i = (x-1)*blo + 1; i <= min(x*blo, n); i++) a[i] = lazy[x];    lazy[x] = 0;}void first_color(int x, int value) {    for (int i = (x-1)*blo + 1; i <= min(x*blo, n); i++) v[i] += abs(value - a[i]), sm[x] += abs(value - a[i]), a[i] = value;}void update(int l, int r, int x) {    if(bl[l] == bl[r]) {        if(lazy[bl[l]]) push_down(bl[l]);        for (int i = l; i <= r; i++) v[i] += abs(a[i] - x), sm[bl[i]] += abs(a[i] - x), a[i] = x;        return ;    }    else {        if(lazy[bl[l]]) push_down(bl[l]);        for (int i = l; i <= bl[l]*blo; i++) {            sm[bl[i]] += abs(a[i] - x);            v[i] += abs(a[i] - x);            a[i] = x;        }        for (int i = bl[l]+1;  i <= bl[r]-1; i++) {            if(lazy[i]) {                bv[i] += abs(x - lazy[i]);                sm[i] += 1LL * blo * abs(x - lazy[i]);                lazy[i] = x;            }            else {                first_color(i, x);                lazy[i] = x;            }        }        if(lazy[bl[r]]) push_down(bl[r]);        for (int i = (bl[r]-1)*blo + 1; i <= r; i++) {            sm[bl[i]] += abs(a[i] - x);            v[i] += abs(a[i] - x);            a[i] = x;        }    }}LL query(int l, int r) {    LL ans = 0;    if(bl[l] == bl[r]){        for (int i = l; i <= r; i++) {            ans += v[i] + bv[bl[i]];        }        return ans;    }    for (int i = l; i <= bl[l]*blo; i++) {        ans += v[i] + bv[bl[i]];    }    for (int i = bl[l]+1; i <= bl[r]-1; i++) {        ans += sm[i];    }    for (int i = (bl[r]-1)*blo+1; i <= r; i++) {        ans += v[i] + bv[bl[i]];    }    return ans;}int main() {    int m, ty, l, r, x;    scanf("%d %d", &n, &m);    blo = sqrt(n);    for (int i = 1; i <= n; i++) {        bl[i] = (i-1)/blo + 1;        a[i] = i;        v[i] = 0;    }    while(m--) {        scanf("%d", &ty);        if(ty == 1) {            scanf("%d %d %d", &l, &r, &x);            update(l, r, x);        }        else {            scanf("%d %d", &l, &r);            printf("%lld\n", query(l, r));        }    }    return 0;}