/* このコード、と~おれ! Be accepted! ∧_∧  (。・ω・。)つ━☆・*。 ⊂   ノ    ・゜+.  しーJ   °。+ *´¨)          .· ´¸.·*´¨) ¸.·*¨)           (¸.·´ (¸.·'* ☆ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include ////多倍長整数, cpp_intで宣言 //#include //using namespace boost::multiprecision; //#pragma GCC target ("avx2") //#pragma GCC optimization ("Ofast") //#pragma GCC optimization ("unroll-loops") //#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native") #define repeat(i, n, m) for(int i = n; i < (m); ++i) #define rep(i, n) for(int i = 0; i < (n); ++i) #define printynl(a) printf(a ? "yes\n" : "no\n") #define printyn(a) printf(a ? "Yes\n" : "No\n") #define printYN(a) printf(a ? "YES\n" : "NO\n") #define printim(a) printf(a ? "possible\n" : "imposible\n") #define printdb(a) printf("%.50lf\n", a) //少数出力 #define printLdb(a) printf("%.50Lf\n", a) //少数出力 #define printdbd(a) printf("%.16lf\n", a) //少数出力(桁少なめ) #define prints(s) printf("%s\n", s.c_str()) //string出力 #define all(x) (x).begin(), (x).end() #define deg_to_rad(deg) (((deg)/360.0L)*2.0L*PI) #define rad_to_deg(rad) (((rad)/2.0L/PI)*360.0L) #define Please return #define AC 0 #define manhattan_dist(a, b, c, d) (abs(a - c) + abs(b - d)) /*(a, b) から (c, d) のマンハッタン距離 */ #define inf numeric_limits::infinity(); #define linf numeric_limits::infinity() using ll = long long; using ull = unsigned long long; constexpr int INF = 1073741823; constexpr int MINF = -1073741823; constexpr ll LINF = ll(4661686018427387903); constexpr ll MOD = 1e9 + 7; constexpr ll mod = 998244353; constexpr long double eps = 1e-6; const long double PI = acosl(-1.0L); using namespace std; void scans(string& str) { char c; str = ""; scanf("%c", &c); if (c == '\n')scanf("%c", &c); while (c != '\n' && c != -1 && c != ' ') { str += c; scanf("%c", &c); } } void scanc(char& str) { char c; scanf("%c", &c); if (c == -1)return; while (c == '\n') { scanf("%c", &c); } str = c; } double acot(double x) { return PI / 2 - atan(x); } ll LSB(ll n) { return (n & (-n)); } template inline T chmin(T& a, const T& b) { if (a > b)a = b; return a; } template inline T chmax(T& a, const T& b) { if (a < b)a = b; return a; } /*-----------------------------------------ここからコード-----------------------------------------*/ /* * @title longest-increasing-subsequence(dp) * @docs kyopro/docs/LIS_dp.md */ //st が true の時、狭義単調増加 int lis(const int& n, const vector& a, const bool& st) { vector dp(n); fill(all(dp), INF); vector::iterator ite; rep(i, n) { if (st)ite = lower_bound(all(dp), a[i]); else ite = upper_bound(all(dp), a[i]); if (ite != dp.end())*ite = a[i]; } return distance(dp.begin(), lower_bound(all(dp), INF)); } int main() { int n; scanf("%d", &n); vector a(n), b; rep(i, n) { scanf("%d", &a[i]); a[i] -= i; if (a[i] > 0)b.push_back(a[i]); } printf("%d\n", n - lis(b.size(), b, false)); Please AC; }