#include <cstdio> #include <cstring> #include <cmath> #include <cassert> #include <iostream> #include <algorithm> #include <iterator> #include <string> #include <vector> #include <queue> #include <bitset> #include <utility> #include <stack> using namespace std; typedef long long LL; typedef pair<int,int> PII; typedef vector<int> VI; #define MP make_pair #define FOR(v,p,k) for(int v=(p);v<=(k);++v) #define FORD(v,p,k) for(int v=(p);v>=(k);--v) #define REP(i,n) for(int i=0;i<(n);++i) #define VAR(v,i) __typeof(i) v=(i) #define FOREACH(i,c) for(VAR(i,(c).begin());i!=(c).end();++i) #define PB push_back #define ST first #define ND second #define SIZE(x) (int)x.size() #define ALL(c) c.begin(),c.end() #define ODD(x) ((x)%2) #define EVEN(x) (!(ODD(x))) int main() { int n; scanf("%d\n", &n); VI pos(n+1); REP(i, n) { int a; scanf("%d", &a); pos[a] = i; } int metric = 2 * n + 1; LL res = 1; if (n == 1) { printf("%d %lld\n", metric, res); return 0; } int req_all_from = n - 1; int old_req_all_from = n - 1; int left = min(pos[req_all_from], pos[n]); int right = max(pos[req_all_from], pos[n]); while (req_all_from >= 1) { FOR(a, req_all_from, old_req_all_from - 1) { left = min(pos[a], left); right = max(pos[a], right); } int x = right - left + 1; old_req_all_from = req_all_from; req_all_from = min(req_all_from, n - x / 2); if (req_all_from == old_req_all_from) { //res++; while ((req_all_from >= 1) && (left <= pos[req_all_from]) && (pos[req_all_from] <= right)) { req_all_from--; } if (req_all_from == 0) { res += ((LL)(n - 1 - right + 1)) * (left + 1); } else { // max (max_diff) : n - (x+max_diff)/2 = req_all_from+1 // 2* (n - (req_all_from +1)) = (x+max_diff) int max_diff = 2 * (n - (req_all_from + 1)) - x; if ((x + max_diff) % 2 == 0) { max_diff++; } //int max_diff = 0; //while (( n - (max_diff + 1 +x) / 2) > req_all_from) { // ++max_diff; //} if (pos[req_all_from] < left) { int min_left = max(pos[req_all_from] + 1, left - max_diff); FOR(i, min_left, left) { int rest = max_diff - (left - i); res += min(n - 1, right + rest) - right + 1; } } else { int max_rigth = min(pos[req_all_from] - 1, right + max_diff); FOR(i, right, max_rigth) { int rest = max_diff - (i - right); res += left - max(0, left - rest) + 1; } } } } } printf("%d %lld\n", metric, res); 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 | #include <cstdio> #include <cstring> #include <cmath> #include <cassert> #include <iostream> #include <algorithm> #include <iterator> #include <string> #include <vector> #include <queue> #include <bitset> #include <utility> #include <stack> using namespace std; typedef long long LL; typedef pair<int,int> PII; typedef vector<int> VI; #define MP make_pair #define FOR(v,p,k) for(int v=(p);v<=(k);++v) #define FORD(v,p,k) for(int v=(p);v>=(k);--v) #define REP(i,n) for(int i=0;i<(n);++i) #define VAR(v,i) __typeof(i) v=(i) #define FOREACH(i,c) for(VAR(i,(c).begin());i!=(c).end();++i) #define PB push_back #define ST first #define ND second #define SIZE(x) (int)x.size() #define ALL(c) c.begin(),c.end() #define ODD(x) ((x)%2) #define EVEN(x) (!(ODD(x))) int main() { int n; scanf("%d\n", &n); VI pos(n+1); REP(i, n) { int a; scanf("%d", &a); pos[a] = i; } int metric = 2 * n + 1; LL res = 1; if (n == 1) { printf("%d %lld\n", metric, res); return 0; } int req_all_from = n - 1; int old_req_all_from = n - 1; int left = min(pos[req_all_from], pos[n]); int right = max(pos[req_all_from], pos[n]); while (req_all_from >= 1) { FOR(a, req_all_from, old_req_all_from - 1) { left = min(pos[a], left); right = max(pos[a], right); } int x = right - left + 1; old_req_all_from = req_all_from; req_all_from = min(req_all_from, n - x / 2); if (req_all_from == old_req_all_from) { //res++; while ((req_all_from >= 1) && (left <= pos[req_all_from]) && (pos[req_all_from] <= right)) { req_all_from--; } if (req_all_from == 0) { res += ((LL)(n - 1 - right + 1)) * (left + 1); } else { // max (max_diff) : n - (x+max_diff)/2 = req_all_from+1 // 2* (n - (req_all_from +1)) = (x+max_diff) int max_diff = 2 * (n - (req_all_from + 1)) - x; if ((x + max_diff) % 2 == 0) { max_diff++; } //int max_diff = 0; //while (( n - (max_diff + 1 +x) / 2) > req_all_from) { // ++max_diff; //} if (pos[req_all_from] < left) { int min_left = max(pos[req_all_from] + 1, left - max_diff); FOR(i, min_left, left) { int rest = max_diff - (left - i); res += min(n - 1, right + rest) - right + 1; } } else { int max_rigth = min(pos[req_all_from] - 1, right + max_diff); FOR(i, right, max_rigth) { int rest = max_diff - (i - right); res += left - max(0, left - rest) + 1; } } } } } printf("%d %lld\n", metric, res); return 0; } |