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| 1 | +class Solution { |
| 2 | + int[][] dp=null; |
| 3 | + public int maxValue(int[][] events, int k) { |
| 4 | + int n = events.length; |
| 5 | + dp = new int[n][k+1]; |
| 6 | + for(int[] d:dp){ |
| 7 | + Arrays.fill(d,-1); |
| 8 | + } |
| 9 | + if(k == 1) { |
| 10 | + for(int[] event : events) { |
| 11 | + max = Math.max(event[2], max); |
| 12 | + } |
| 13 | + return max; |
| 14 | + } |
| 15 | + |
| 16 | + Arrays.sort(events,(a,b) -> a[0]==b[0]?a[1]-b[1]:a[0]-b[0]); |
| 17 | + |
| 18 | + return helper(events,0,k,n); //o(N*K) * O(logN) |
| 19 | + } |
| 20 | + |
| 21 | + int helper(int[][] events,int pos,int k,int n){ |
| 22 | + if(pos>=n || k==0){ |
| 23 | + return 0; |
| 24 | + } |
| 25 | + |
| 26 | + if(dp[pos][k]>-1){ |
| 27 | + return dp[pos][k]; |
| 28 | + } |
| 29 | + |
| 30 | + int nextPos = nextEvent(events,pos,n); // O(logN) |
| 31 | + int select = events[pos][2] + helper(events,nextPos,k-1,n); |
| 32 | + int reject = helper(events,pos+1,k,n); |
| 33 | + dp[pos][k]= Math.max(select,reject); |
| 34 | + return dp[pos][k]; |
| 35 | + } |
| 36 | + |
| 37 | + int nextEvent(int[][] events,int pos, int n){ |
| 38 | + int endDay = events[pos][1]; |
| 39 | + pos++; |
| 40 | + while(pos<n){ |
| 41 | + int mid = pos + (n-pos)/2; |
| 42 | + if(events[mid][0]>endDay){ |
| 43 | + n =mid; |
| 44 | + } |
| 45 | + else{ |
| 46 | + pos = mid+1; |
| 47 | + } |
| 48 | + } |
| 49 | + return n; |
| 50 | + } |
| 51 | +} |
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