#pragma GCC optimize ("Ofast") #define _USE_MATH_DEFINES #include <bits/stdc++.h> #define FOR(i, a, b) for (auto i=(a); i<(b); i++) #define FORD(i, a, b) for (int i=(a); i>(b); i--) #define SZ(x) ((int)(x).size()) #define ALL(x) (x).begin(), (x).end() #define PPC(x) __builtin_popcountll(x) #define MSB(x) (63 - __builtin_clzll(x)) #define LSB(x) __builtin_ctz(x) #define ARG(x, i) (get<i>(x)) #define ithBit(m, i) ((m) >> (i) & 1) #define pb push_back #define ft first #define sd second #define kw(a) ((a) * (a)) #ifdef DEBUG #include "debug.h" #else #define dbg(...) 0 #endif using namespace std; template <typename T1, typename T2> inline void remin(T1& a, T2 b) { a = min(a, (T1)b); } template <typename T1, typename T2> inline void remax(T1& a, T2 b) { a = max(a, (T1)b); } const int maxN = 1 << 19, maxTS = maxN * 2, mod = 1'000'000'007; template <typename T1, typename T2> inline void addMod(T1& a, T2 b) { a = (a + b) % mod; } template <typename Tp> struct Tree_t { int offset, qbegin, qend; Tp T[maxTS], res; void qpriv(int v, int left, int right) { if (left >= qend or right <= qbegin) return; if (left >= qbegin and right <= qend) { res += T[v]; return; } qpriv(v * 2, left, (left + right) / 2); qpriv(v*2+1, (left + right) / 2, right); } void init(int n) { for (offset = 1; offset < n; offset *= 2) ; } void updt(int v, long long dx) { for (v += offset; v != 0; v /= 2) T[v] += dx; } Tp query(int a, int b) { qbegin = a + offset; qend = b + offset; res = 0; qpriv(1, offset, offset * 2); return res % mod; } }; using Tree = Tree_t <long long>; Tree tree[2][2]; int T[maxN]; void solve() { int n; scanf ("%d", &n); map <int, int> leaf {{0, 1}}; long long pref = 0; FOR(i, 1, n+1) { scanf ("%d", T+i); addMod(pref, T[i]); leaf[pref] = 1; } int s = 0; for (auto& it : leaf) it.sd = s++; FOR(a, 0, 2) FOR(b, 0, 2) tree[a][b].init(s); tree[0][0].updt(0, 1); pref = 0; long long dp = 0; FOR(i, 1, n+1) { pref += T[i]; long long r = pref % mod, p = pref / mod; int a = pref & 1, b = p & 1, v = leaf[r]; dp = 0; FOR(x, 0, 2) FOR(y, 0, 2) { bool ok = (a^x) == (b^y); int left = ok ? 0 : v+1; int right = ok ? v+1 : s; dp += tree[x][y].query(left, right); } dp %= mod; tree[a][b].updt(v, dp); } printf("%lld\n", dp); } int main() { int t = 1; //scanf ("%d", &t); FOR(tid, 1, t+1) { //printf("Case #%d: ", tid); solve(); } return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 | #pragma GCC optimize ("Ofast") #define _USE_MATH_DEFINES #include <bits/stdc++.h> #define FOR(i, a, b) for (auto i=(a); i<(b); i++) #define FORD(i, a, b) for (int i=(a); i>(b); i--) #define SZ(x) ((int)(x).size()) #define ALL(x) (x).begin(), (x).end() #define PPC(x) __builtin_popcountll(x) #define MSB(x) (63 - __builtin_clzll(x)) #define LSB(x) __builtin_ctz(x) #define ARG(x, i) (get<i>(x)) #define ithBit(m, i) ((m) >> (i) & 1) #define pb push_back #define ft first #define sd second #define kw(a) ((a) * (a)) #ifdef DEBUG #include "debug.h" #else #define dbg(...) 0 #endif using namespace std; template <typename T1, typename T2> inline void remin(T1& a, T2 b) { a = min(a, (T1)b); } template <typename T1, typename T2> inline void remax(T1& a, T2 b) { a = max(a, (T1)b); } const int maxN = 1 << 19, maxTS = maxN * 2, mod = 1'000'000'007; template <typename T1, typename T2> inline void addMod(T1& a, T2 b) { a = (a + b) % mod; } template <typename Tp> struct Tree_t { int offset, qbegin, qend; Tp T[maxTS], res; void qpriv(int v, int left, int right) { if (left >= qend or right <= qbegin) return; if (left >= qbegin and right <= qend) { res += T[v]; return; } qpriv(v * 2, left, (left + right) / 2); qpriv(v*2+1, (left + right) / 2, right); } void init(int n) { for (offset = 1; offset < n; offset *= 2) ; } void updt(int v, long long dx) { for (v += offset; v != 0; v /= 2) T[v] += dx; } Tp query(int a, int b) { qbegin = a + offset; qend = b + offset; res = 0; qpriv(1, offset, offset * 2); return res % mod; } }; using Tree = Tree_t <long long>; Tree tree[2][2]; int T[maxN]; void solve() { int n; scanf ("%d", &n); map <int, int> leaf {{0, 1}}; long long pref = 0; FOR(i, 1, n+1) { scanf ("%d", T+i); addMod(pref, T[i]); leaf[pref] = 1; } int s = 0; for (auto& it : leaf) it.sd = s++; FOR(a, 0, 2) FOR(b, 0, 2) tree[a][b].init(s); tree[0][0].updt(0, 1); pref = 0; long long dp = 0; FOR(i, 1, n+1) { pref += T[i]; long long r = pref % mod, p = pref / mod; int a = pref & 1, b = p & 1, v = leaf[r]; dp = 0; FOR(x, 0, 2) FOR(y, 0, 2) { bool ok = (a^x) == (b^y); int left = ok ? 0 : v+1; int right = ok ? v+1 : s; dp += tree[x][y].query(left, right); } dp %= mod; tree[a][b].updt(v, dp); } printf("%lld\n", dp); } int main() { int t = 1; //scanf ("%d", &t); FOR(tid, 1, t+1) { //printf("Case #%d: ", tid); solve(); } return 0; } |