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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. #define ll long long
  4. #define mapll map<ll,ll>
  5. #define mapint map<int,int>
  6. #define pb push_back
  7. #define f(i, n) for (ll i = 0; i < n; i++)
  8. #define in(a, n) vector<ll> a(n); f(i, n) cin >> a[i];
  9. #define MOD 1000000007
  10. #define eod cout<<endl;return
  11.  
  12. bool isPrime(ll n);
  13. ll lg(ll a, ll b);
  14. ll power(ll a, ll b, ll mod = MOD);
  15. ll sumofdigits(ll x);
  16. ll factors(ll x);
  17.  
  18. void solve() {
  19.    ll n,k;cin>>n>>k;
  20.    ll a[n+1];
  21.    for(int i=1;i<=n;i++){cin>>a[i];}
  22.    mapll mp1,mp2;
  23.    ll sum=0;
  24.    mp1[0]=1;
  25.    for(int i=1;i<=n;i++){
  26.        if(!mp1[sum] && sum!=0){
  27.        mp1[sum]=i;}
  28.        sum+=a[i];
  29.    }
  30.    sum=0;
  31.    mp2[0]=0;
  32.    for(int i=n;i>=1;i--){
  33.      if(!mp2[sum] && sum!=0){
  34.        mp2[sum]=n-i;}
  35.        sum+=a[i];
  36.    }ll ans=0;
  37.    for(auto [x,y]:mp1){
  38.        if((sum-x-k)==0){ans=max(n-y+1,ans);}
  39.        else if(mp2[sum-x-k]){ans=max(n-y+1-mp2[sum-x-k],ans);}
  40.    }
  41.    cout<<ans<<endl;
  42.  
  43.  
  44. }
  45.  
  46. int main() {
  47.    std::ios::sync_with_stdio(false);
  48.    std::cin.tie(nullptr); std::cout.tie(nullptr);
  49.  
  50.     solve();
  51.     return 0;
  52. }
  53.  
  54. bool isPrime(ll n) {
  55.     if (n <= 1) return false;
  56.     if (n == 2 || n == 3) return true;
  57.     for (ll i = 2; i * i <= n; ++i) {
  58.         if (n % i == 0) return false;
  59.     }
  60.     return true;
  61. }
  62.  
  63. ll lg(ll a, ll b) {
  64.     if (b <= 1 || a < b) return 0;
  65.     ll k = 0;
  66.     while (a >= b) {
  67.         a /= b;
  68.         k++;
  69.     }
  70.     return k;
  71. }
  72.  
  73. ll power(ll a, ll b, ll mod) {
  74.     ll res = 1;
  75.     while (b) {
  76.         if (b & 1) res = (res * a) % mod;
  77.         a = (a * a) % mod;
  78.         b >>= 1;
  79.     }
  80.     return res;
  81. }
  82.  
  83. ll sumofdigits(ll x) {
  84.     ll k = 0;
  85.     while (x > 0) {
  86.         k += x % 10;
  87.         x /= 10;
  88.     }
  89.     return k;
  90. }
  91.  
  92. ll factors(ll x) {
  93.     ll f = 0;
  94.     for (ll i = 1; i * i <= x; i++) {
  95.         if (x % i == 0) {
  96.             f += 2;
  97.             if (x == i * i) f--;
  98.         }
  99.     }
  100.     return f;
  101. }
Success #stdin #stdout 0.01s 5296KB
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https://ideone.com/KkxWrX
language:
C++14 (gcc 8.3)
created:
12 days ago
visibility:
public

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