Create 2018-roundA-contention.cpp

Author: tmp-coder

Diff for: kick-start/2018-roundA-contention.cpp

@@ -0,0 +1,97 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+#define INF 0x3f3f3f3f
+#define INF64 0x3f3f3f3f3f3f3f3f
+#define ms(x,v) memset(x,(v),sizeof(x))
+
+typedef long long LL;
+typedef pair<int,int> PII;
+typedef tuple<int,int,int> TIII;
+typedef pair<PII,int> PIII;
+const int MAXN = 1e6+10;
+
+int n, q;
+vector<PII> book;
+
+bool ok(int k){
+    if(k==0)return true;
+    vector<int> bg(q,0);
+
+    for(int i=0 ; i< q ; ++i){
+        int sweep_to = max(book[i].first,bg[i]),ed = book[i].second;
+        int next_start = ed;
+        int cnt =0;
+
+        for(int j=i+1 ; j < q ; ++j){
+            int l = book[j].first,r = book[j].second;
+            if(l >ed)break;
+            if(r <= ed){// must before the ith booking
+                if(l >sweep_to)cnt += l - sweep_to;
+                sweep_to = max(sweep_to,r);
+                if(cnt >=k){// just ok
+                    next_start = l - (cnt -k);
+                    break;
+                }
+            }
+        }
+        assert(sweep_to <= ed);
+        if(cnt <k){
+            cnt += ed - sweep_to;
+            if(cnt <k)return false;
+            next_start = ed - (cnt - k);
+        }
+
+        // update left start point
+
+        for(int j = i+1; j<q ; ++j){
+            int l = book[j].first,r = book[j].second;
+            if(l>=next_start)break;// can book before ith booking
+            if(book[j].second > ed){// those booking must after ith booking 
+                bg[j] = max(bg[j],ed);
+            }
+        }
+    }
+    return true;
+}
+
+
+int solve(){
+    sort(book.begin(), book.end());
+    int lo =0,hi = n;
+    while(lo <= hi){
+        int mid = (hi + lo) >> 1;
+        if(ok(mid))lo = mid +1;
+        else hi = mid -1;
+    }
+    assert(lo-1>=0);
+    return lo -1;
+}
+
+int main(){
+
+    ios :: sync_with_stdio(0);
+    cin.tie(0);
+    std::cout.precision(8);
+    std::cout.setf( std::ios::fixed, std:: ios::floatfield );
+   
+    int T;
+    cin >> T;
+    // cout << "T = " << T << "\n";
+    for(int t =1 ; t <= T; ++t){
+
+        cin >> n >> q;
+        book.resize(q);
+        for(int i=0 ; i<q ; ++i)
+        {
+            int l,r;
+            cin >> l >> r;
+            book[i] = {--l,r};
+        }
+
+        auto ans = solve();
+        std::cout << "Case #"<<t<<": "<<ans<<"\n";
+    }
+    return 0;
+}