luoguP3374 【模板】树状数组 1 cdq

链接

luogu

思路

可耐我连cdq都不会，Orz 陈丹琦

代码

#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 7;
int read() {
    int x = 0, f = 1; char s = getchar();
    for (;s > '9' || s < '0'; s = getchar()) if (s == '-') f = -1;
    for (;s >= '0' && s <= '9'; s = getchar()) x = x * 10 + s - '0';
    return x * f;
}
int ans[N];
struct node {
    int type, id, val;
    node(int a = 0,int b = 0, int c = 0) {
        type = a, id = b, val = c;
    }
    bool operator < (const node &b) const {
        return id == b.id ? type < b.type : id < b.id;
    }
} Q[N<<2], tmp[N<<2];
void cdq(int l, int r){
    if (l == r) return;
    int mid = (l + r) >> 1;
    cdq(l, mid), cdq(mid + 1, r);
    int p = l, q = mid + 1, js = l, sum = 0;
    while (p <= mid && q <= r) {
        if (Q[p] < Q[q]) {
            if (Q[p].type == 1) sum += Q[p].val;
            tmp[js++] = Q[p++];
        } else {
            if (Q[q].type == 2) ans[Q[q].val] -= sum;
            if (Q[q].type == 3) ans[Q[q].val] += sum;
            tmp[js++] = Q[q++];
        }
    }
    while (p <= mid) tmp[js++] = Q[p++];
    while (q <= r) {
        if (Q[q].type == 2) ans[Q[q].val] -= sum;
        if (Q[q].type == 3) ans[Q[q].val] += sum;
        tmp[js++] = Q[q++];
    } 
    for (int i = l; i <= r; ++i) Q[i] = tmp[i];
}
int main() {
    int n = read(), m = read(), js = 0, DSR = 0;
    for (int i = 1; i <= n; ++i) {
        int x = read();
        Q[++js] = node(1, i, x);
    }
    for(int i = 1; i <= m; ++i) {
        int opt = read(), x = read(), y = read();
        if (opt == 1) {
            Q[++js] = node(1, x, y);
        } else {
            Q[++js] = node(2, x-1, ++DSR),
            Q[++js] = node(3, y, DSR);
        }
    }
    cdq(1, js);
    for (int i = 1; i <= DSR; ++i) printf("%d\n", ans[i]);
    return 0;
}