6 条题解
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1
#include <bits/stdc++.h> #define ll long long #define N 100000 using namespace std; int sz[N], rev[N], tag[N], sum[N], ch[N][2], fa[N], val[N]; int n, m, rt, x; void push_up(int x){ sz[x] = sz[ch[x][0]] + sz[ch[x][1]] + 1; sum[x] = sum[ch[x][1]] + sum[ch[x][0]] + val[x]; } void push_down(int x){ if(rev[x]){ swap(ch[x][0], ch[x][1]); if(ch[x][1]) rev[ch[x][1]] ^= 1; if(ch[x][0]) rev[ch[x][0]] ^= 1; rev[x] = 0; } if(tag[x]){ if(ch[x][1]) tag[ch[x][1]] += tag[x], sum[ch[x][1]] += tag[x]; if(ch[x][0]) tag[ch[x][0]] += tag[x], sum[ch[x][0]] += tag[x]; tag[x] = 0; } } void rotate(int x, int &k){ int y = fa[x], z = fa[fa[x]]; int kind = ch[y][1] == x; if(y == k) k = x; else ch[z][ch[z][1]==y] = x; fa[x] = z; fa[y] = x; fa[ch[x][!kind]] = y; ch[y][kind] = ch[x][!kind]; ch[x][!kind] = y; push_up(y); push_up(x); } void splay(int x, int &k){ while(x != k){ int y = fa[x], z = fa[fa[x]]; if(y != k) if(ch[y][1] == x ^ ch[z][1] == y) rotate(x, k); else rotate(y, k); rotate(x, k); } } int kth(int x, int k){ push_down(x); int r = sz[ch[x][0]]+1; if(k == r) return x; if(k < r) return kth(ch[x][0], k); else return kth(ch[x][1], k-r); } void split(int l, int r){ int x = kth(rt, l), y = kth(rt, r+2); splay(x, rt); splay(y, ch[rt][1]); } void rever(int l, int r){ split(l, r); rev[ch[ch[rt][1]][0]] ^= 1; } void add(int l, int r, int v){ split(l, r); tag[ch[ch[rt][1]][0]] += v; val[ch[ch[rt][1]][0]] += v; push_up(ch[ch[rt][1]][0]); } int build(int l, int r, int f){ if(l > r) return 0; if(l == r){ fa[l] = f; sz[l] = 1; return l; } int mid = l + r >> 1; ch[mid][0] = build(l, mid-1, mid); ch[mid][1] = build(mid+1, r, mid); fa[mid] = f; push_up(mid); return mid; } int asksum(int l, int r){ split(l, r); return sum[ch[ch[rt][1]][0]]; } int main(){ n = 2; rt = build(1, n+2, 0); for(int i = 1; i <= n; i++){ scanf("%d", &x); add(i, i, x) } rever(1, n); printf("%d\n", asksum(1, n)); return 0; }
- 1
信息
- ID
- 207
- 时间
- 1000ms
- 内存
- 128MiB
- 难度
- 7
- 标签
- (无)
- 递交数
- 159
- 已通过
- 41
- 上传者