Problem Info
http://www.usaco.org/index.php?page=viewproblem2&cpid=815
My Work
/*#include <bits/stdc++.h>
using namespace std;
using str = string; // yay python!
using ld = long double; // or double, if TL is tight
using ll = long long;
using int64 = ll;
using db = double;
using ull = unsigned long long;
#define ch() getchar()
#define pc(x) putchar(x)
#define tcT template<class T
#define tcTU tcT, class U
tcT> using V = vector<T>;
tcT, size_t SZ> using AR = array<T,SZ>;
using vi = V<int>;
using vb = V<bool>;
using vpi = V<pair<int,int>>;
using vvi = V<vi>;
using vl = V<ll>;
using vd = V<ld>;
using vstr = V<str>;
#define all(x) begin(x), end(x)
#define sor(x) sort(all(x))
#define rev(x) reverse(all(x))
#define sz(x) (int)(x).size()
#define rall(x) x.rbegin(), x.rend()
#define AR array
// loops
#define F0R(i, a, b) for (int i=a; i<b;++i)
#define FOR(i, a) for (int i=0; i<a;++i)
#define FORn(i, a) for (int i=1; i<=a;++i)
#define ROF(i,a) for(int i=a-1; i >= 0;--i)
#define R0F(i,a,b) for(int i=a; i > b;--i)
#define ROFn(i,a) for(int i=a; i > 0;--i)
#define rep(a) F0R(_, a)
#define trav(i,x) for(auto& i:x)
// pairs
#define mp make_pair
#define pi pair <int, int>
#define f first
#define s second
// vectors
#define lb lower_bound
#define ub upper_bound
#define SUM(v) accumulate(all(v), 0LL)
#define MN(v) *min_element(all(v))
#define MX(v) *max_element(all(v))
#define eb emplace_back
#define ft front()
#define bk back()
#define ins insert
#define pf push_front
#define pb push_back
#define emt empty()
#define rsz resize
#define pob pop_back()
#define pof pop_front()
#define swp(a,b) a^=b^=a^=b
#define ts to_string
#define setIO() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
const ll MOD = 1e9+7;
const ll MAX = 100000000000;
const ll INF = 1e18; // not too close to LLONG_MAX
const ld PI = acos((ld)-1);
#ifdef _DEBUG
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1}; // for every grid problem!!
tcT> bool ckmin(T& a, const T& b) {
return b < a ? a = b, 1 : 0; } // set a = min(a,b)
tcT> bool ckmax(T& a, const T& b) {
return a < b ? a = b, 1 : 0; }
tcTU> T fstTrue(T lo, T hi, U f) {
hi ++; assert(lo <= hi); // assuming f is increasing
while (lo < hi) { // find first index such that f is true
T mid = lo+(hi-lo)/2;
f(mid) ? hi = mid : lo = mid+1;
}
return lo;
}
tcTU> T lstTrue(T lo, T hi, U f) {
lo --; assert(lo <= hi); // assuming f is decreasing
while (lo < hi) { // find first index such that f is true
T mid = lo+(hi-lo+1)/2;
f(mid) ? lo = mid : hi = mid-1;
}
return lo;
}
//INPUT
#define tcTUU tcT, class ...U
tcT> void re(complex<T>& c);
tcTU> void re(pair<T,U>& p);
tcT> void re(V<T>& v);
tcT, size_t SZ> void re(AR<T,SZ>& a);
tcT> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
tcTUU> void re(T& t, U&... u) { re(t); re(u...); }
tcT> void re(complex<T>& c) { T a,b; re(a,b); c = {a,b}; }
tcTU> void re(pair<T,U>& p) { re(p.f,p.s); }
tcT> void re(V<T>& x) { trav(a,x) re(a); }
tcT> void rv(int n, V<T>& x) { x.rsz(n); re(x); }
//OUTPUT
namespace output {
tcT> void prv(V<T>& x) { FOR(i,sz(x)) cout << x[i] << " \n"[i + 1 == sz(x)];}
template<class T1, class T2> void pr(const pair<T1,T2>& x);
tcT, size_t SZ> void pr(const array<T,SZ>& x);
tcT> void pr(const vector<T>& x);
tcT> void pr(const set<T>& x);
template<class T1, class T2> void pr(const map<T1,T2>& x);
tcT> void pr(const T& x) { cout << x; }
template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
pr(first); pr(rest...);
}
template<class T1, class T2> void pr(const pair<T1,T2>& x) {
pr("{",x.f,", ",x.s,"}");
}
tcT> void prContain(const T& x) {
pr("{");
bool fst = 1; trav(a,x) pr(!fst?", ":"",a), fst = 0;
pr("}");
}
tcT, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
tcT> void pr(const vector<T>& x) { prContain(x); }
tcT> void pr(const set<T>& x) { prContain(x); }
template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
template<class Arg> void ps(const Arg& first) { pr(first,"\n"); } // print w/ spaces
template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
pr(first," "); ps(rest...);
}
}
using namespace output;
template<int MOD, int RT> struct mint {
static const int mod = MOD;
static constexpr mint rt() { return RT; } // primitive root for FFT
int v; explicit operator int() const { return v; } // explicit -> don't silently convert to int
mint():v(0) {}
mint(ll _v) { v = int((-MOD < _v && _v < MOD) ? _v : _v % MOD);
if (v < 0) v += MOD; }
bool operator==(const mint& o) const {
return v == o.v; }
friend bool operator!=(const mint& a, const mint& b) {
return !(a == b); }
friend bool operator<(const mint& a, const mint& b) {
return a.v < b.v; }
friend void re(mint& a) { ll x; re(x); a = mint(x); }
friend str ts(mint a) { return ts(a.v); }
mint& operator+=(const mint& o) {
if ((v += o.v) >= MOD) v -= MOD;
return *this; }
mint& operator-=(const mint& o) {
if ((v -= o.v) < 0) v += MOD;
return *this; }
mint& operator*=(const mint& o) {
v = int((ll)v*o.v%MOD); return *this; }
mint& operator/=(const mint& o) { return (*this) *= inv(o); }
friend mint pow(mint a, ll p) {
mint ans = 1; assert(p >= 0);
for (; p; p /= 2, a *= a) if (p&1) ans *= a;
return ans; }
friend mint inv(const mint& a) { assert(a.v != 0);
return pow(a,MOD-2); }
mint operator-() const { return mint(-v); }
mint& operator++() { return *this += 1; }
mint& operator--() { return *this -= 1; }
friend mint operator+(mint a, const mint& b) { return a += b; }
friend mint operator-(mint a, const mint& b) { return a -= b; }
friend mint operator*(mint a, const mint& b) { return a *= b; }
friend mint operator/(mint a, const mint& b) { return a /= b; }
};
void setF(string fileName = "") {
ios_base::sync_with_stdio(0); cin.tie(0);
if((int)fileName.size()) {
freopen((fileName+".in").c_str(), "r", stdin);
freopen((fileName+".out").c_str(), "w", stdout);
}
}
struct DSU {
vector<int> e;
DSU(int N) { e = vector<int>(N, -1); }
int get(int x) { return e[x] < 0 ? x : e[x] = get(e[x]); }
bool same_set(int a, int b) { return get(a) == get(b); }
int size(int x) { return -e[get(x)]; }
bool unite(int x, int y) { // union by size
x = get(x), y = get(y);
if (x == y) return false;
if (e[x] > e[y]) swap(x, y);
e[x] += e[y]; e[y] = x;
return true;
}
};
struct edge{
int a;
int b;
int w;
};
ll bpow(ll x, ll y){
ll res = 1LL;
while(y){
if (y & 1LL)
res *= x;
res %= MOD;
x = (x*x) % MOD;
y >>= 1LL;
}
return res;
}
ll gauss(ll n) { return n * (n + 1ll) / 2; }
ll fact(ll x) { if(x) return x * (x - 1); return 1; }
/*
scanf("%lld", &testInteger);
printf("%lld", testInteger);
____ ____ ____ ____ ____ ____
||f |||l |||o |||p |||p ||||y ||
||__|||__|||__|||__|||__||||__||
|/__\|/__\|/__\|/__\|/__\||/__\|
**/
/*
void solve(){
setF("taming");
int N; cin >> N;
vi A(N); re(A);
vvi dp(N + 2,vi(N + 2));
FORn(k,N){
ROF(i,N){
int cur = 0;
F0R(j,i,N - k + 1){
cur += j - i == A[j];
dp[k][i] = max(dp[k][i],cur + dp[k - 1][j + 1]);
}
if(k == 1) ckmax(dp[k][i],cur);
}
}
FORn(i,N) ps(N - MX(dp[i]));
}
main()
{ setIO();
solve();
}
// look out for out of bounds arrays
//is y a vowel? Damian:1
// <3 :L ._. <_<
//You have no idea how high I can fly
*/
Add explanation of code here
I did a dp which wants to find the maximum number of similar numbers that can be achieved after k points where we place a 0 ( the start of a new interval). It works in O(N^3)
Question
I get wrong answer in 5 out of 11 tests, what is wrong ? I know that the editorial recommends another solution but I can’t figure out a reason why this code wouldn’t work either.