Update 1644 - Maximum Subarray Sum II.cpp

Author: mrsac7

src/1644 - Maximum Subarray Sum II.cpp

@@ -5,81 +5,50 @@ Author: Sachin Srivastava (mrsac7)
 */
 #include<bits/stdc++.h>
 using namespace std;
-template<typename... T>
-void see(T&... args) { ((cin >> args), ...);}
-template<typename... T>
-void put(T&&... args) { ((cout << args << " "), ...);}
-template<typename... T>
-void putl(T&&... args) { ((cout << args << " "), ...); cout<<'\n';}
-#define error(args...) { string _s = #args; replace(_s.begin(), _s.end(), ',', ' '); stringstream _ss(_s); istream_iterator<string> _it(_ss); err(_it, args); }
-void err(istream_iterator<string> it) {}
-template<typename T, typename... Args>
-void err(istream_iterator<string> it, T a, Args... args) {cerr << *it << "=" << a << ", "; err(++it, args...);}
+
 #define int long long
-#define pb push_back
-#define F first
-#define S second
-#define ll long long
-#define ull unsigned long long
-#define ld long double
-#define pii pair<int,int>
-#define vi vector<int>
-#define vii vector<pii>
-#define vc vector
-#define L cout<<'\n';
-#define E cerr<<'\n';
-#define all(x) x.begin(),x.end()
-#define rep(i,a,b) for (int i=a; i<b; ++i)
-#define rev(i,a,b) for (int i=a; i>b; --i)
-#define IOS ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
-#define setpr(x) cout<<setprecision(x)<<fixed
-#define sz size()
-#define seea(a,x,y) for(int i=x;i<y;i++){cin>>a[i];}
-#define seev(v,n) for(int i=0;i<n;i++){int x; cin>>x; v.push_back(x);}
-#define sees(s,n) for(int i=0;i<n;i++){int x; cin>>x; s.insert(x);}
-const ll inf = INT_MAX;
-const ld ep = 0.0000001;
-const ld pi = acos(-1.0);
-const ll md = 1000000007;
+#define endl '\n'
 
-void solve(){
-    int n,a,b; see(n,a,b);
-    int arr[n+1];
-    seea(arr,1,n+1);
-    int pre[n+1]={0};
-    rep(i,1,n+1) pre[i] = pre[i-1]+arr[i]; 
-    int s=0,l=a;
-    rep(i,1,a+1) s+=arr[i];
-    int mx = s;
-    rep(i,a+1,n+1){
-        int x = pre[i]-pre[i-a];
-        if (l==b){
-            s = max(x,s+arr[i]-arr[i-l]);
-            if (s==x) l=a;
-        }
-        else { 
-            s = max(x,s+arr[i]);
-            if (s==x) l=a;
-            else l++;
-        }
-        mx = max(mx,s);
-    }
-    put(mx);
-}    
 signed main(){
-    IOS;
+    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
     #ifdef LOCAL
     freopen("input.txt", "r" , stdin);
     freopen("output.txt", "w", stdout);
     #endif
-    int t=1;
-    //cin>>t;
-    while(t--){
-        solve();
-        //cout<<'\n';
+    
+    int n,x,y; cin>>n>>x>>y;
+    int a[n];
+    for (int i = 0; i < n; i++)
+        cin>>a[i];
+    int pre[n+1] = {0};
+    for (int i = 1; i <= n; i++) 
+        pre[i] = pre[i-1] + a[i-1];
+    int s = 0, len = x;
+    set<pair<int,int>> st;
+    for (int i = 0; i < x; i++)
+        s += a[i];
+    st.insert({pre[1], 0});
+    int mx = s;
+    for (int i = x; i < n; i++) {
+        int z = pre[i+1] - pre[i+1-x];
+        if (len == y) {
+            auto it = st.begin();
+            s = max(z, s + a[i] - (it->first - pre[i-len]));
+            if (s == z) len = x, st.clear();
+            else {
+                for (int k = i-y; k <= it->second; k++)
+                    st.erase({pre[k+1], k});
+                len = i - it->second;
+            }
+            st.insert({pre[i-x+2], i-x+1});
+        }
+        else {
+            s = max(z, s + a[i]);
+            if (s == z) len = x, st.clear();
+            else len++;
+            st.insert({pre[i-x+2], i-x+1});
+        }
+        mx = max(mx, s);
     }
-    #ifdef LOCAL
-    clock_t tStart = clock();
-    cerr<<fixed<<setprecision(10)<<"\nTime Taken: "<<(double)(clock()- tStart)/CLOCKS_PER_SEC<<endl;
-    #endif
-}
+    cout<<mx;
+}