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Codeforces 877F Ann and Books 莫隊

unsigned ans r+ signed def bsp color ORC ann

轉換成前綴和, 預處理一下然後莫隊。

#include<bits/stdc++.h>
#define LL long long
#define fi first
#define se second
#define mk make_pair
#define PLL pair<LL, LL>
#define PLI pair<LL, int>
#define PII pair<int, int>
#define SZ(x) ((int)x.size())
#define ull unsigned long long
using
namespace std; const int N = 2e5 + 7; const int inf = 0x3f3f3f3f; const LL INF = 0x3f3f3f3f3f3f3f3f; const int mod = 1e9 + 7; const double eps = 1e-8; const int B = 300; struct Qus { int L, R, id; bool operator < (const Qus& rhs) const { if(L / B == rhs.L / B) return
R < rhs.R; return L / B < rhs.L / B; } } qus[N]; int n, k, q, l, r, tot, t[N]; int after[N], befor[N], cnt[N]; LL ans[N], a[N], hs[N], val; int main() { scanf("%d%d", &n, &k); for(int i = 1; i <= n; i++) scanf("%d", &t[i]); for(int i = 1; i <= n; i++) { scanf(
"%d", &a[i]); if(t[i] == 1) a[i] = a[i - 1] + a[i]; else a[i] = a[i - 1] - a[i]; hs[tot++] = a[i]; } hs[tot++] = 0; sort(hs, hs + tot); tot = unique(hs, hs + tot) - hs; for(int i = 0; i <= n; i++) a[i] = lower_bound(hs, hs + tot, a[i]) - hs; for(int i = 0, p; i < tot; i++) { after[i] = befor[i] = -1; p = lower_bound(hs, hs + tot, hs[i] + k) - hs; if(p < n && hs[p] == hs[i] + k) after[i] = p; p = lower_bound(hs, hs + tot, hs[i] - k) - hs; if(p < n && hs[p] == hs[i] - k) befor[i] = p; } scanf("%d", &q); for(int i = 1; i <= q; i++) { scanf("%d%d", &qus[i].L, &qus[i].R); qus[i].id = i; qus[i].L--; } sort(qus + 1, qus + 1 + q); l = 0, r = -1; for(int i = 1; i <= q; i++) { int L = qus[i].L, R = qus[i].R, id = qus[i].id; while(r < R) r++, val += befor[a[r]] == -1 ? 0 : cnt[befor[a[r]]], cnt[a[r]]++; while(l > L) l--, val += after[a[l]] == -1 ? 0 : cnt[after[a[l]]], cnt[a[l]]++; while(r > R) cnt[a[r]]--, val -= befor[a[r]] == -1 ? 0 : cnt[befor[a[r]]], r--; while(l < L) cnt[a[l]]--, val -= after[a[l]] == -1 ? 0 : cnt[after[a[l]]], l++; ans[id] = val; } for(int i = 1; i <= q; i++) printf("%lld\n", ans[i]); puts(""); return 0; } /* */

Codeforces 877F Ann and Books 莫隊