Codeforces 444 C - DZY Loves Colors

C - DZY Loves Colors

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<bits/stdc++.h>
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<LL, LL>
#define pii pair<int, int>
#define piii pair<pii, int>
#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);
//head

const int N = 1e5 + , M = ;
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-)*blo + ; i <= min(x*blo, n); i++) a[i] = lazy[x];
    lazy[x] = ;
}
void first_color(int x, int value) {
    for (int i = (x-)*blo + ; 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]+;  i <= bl[r]-; 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]-)*blo + ; 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 = ;
    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]+; i <= bl[r]-; i++) {
        ans += sm[i];
    }
    for (int i = (bl[r]-)*blo+; 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 = ; i <= n; i++) {
        bl[i] = (i-)/blo + ;
        a[i] = i;
        v[i] = ;
    }
    while(m--) {
        scanf("%d", &ty);
        if(ty == ) {
            scanf("%d %d %d", &l, &r, &x);
            update(l, r, x);
        }
        else {
            scanf("%d %d", &l, &r);
            printf("%lld\n", query(l, r));
        }
    }
    return ;
}