Top Coder SRM 582 DIV2 1000

没有想到好的算法，用回溯法给爆破了。。。

public class ColorTheCells{
    private int min_time;
    
    public int minimalTime(int[] dryingTime){
        int len = dryingTime.length;
        int[] dryThen = new int[len];
        int i;
        
        for(i=0;i<len;i++)
            dryThen[i] = 0;
            
        min_time = 0x7fffffff;
        for(i=0;i<len;i++)
            paint(dryThen,dryingTime,0,i,0);
            
        return min_time;
    }
    private void paint(int[] dryThen,int[] dryTime,int cur_cell,int next_cell,int cur_time){
    //1.move to next_cell
    //2.paint
    //3.check time,then paint next or return
    //4.unpaint
        int len = dryThen.length;
        //step 1
        while(cur_cell>next_cell+1){
        //move left
            //wait to move
            if(dryThen[cur_cell - 1]>cur_time)
                cur_time = dryThen[cur_cell-1];
            //move
            cur_time++;
            cur_cell--;
        }
        while(cur_cell<next_cell-1){
        //move right
            //wait to move
            if(dryThen[cur_cell+1]>cur_time)
                cur_time = dryThen[cur_cell+1];
                
            //move
            cur_time++;
            cur_cell++;
        }
        if(cur_cell==next_cell){
        //move left or right
             
            if(cur_cell>0&&cur_cell<len-1){
                if(dryThen[cur_cell-1]<dryThen[cur_cell+1]){
                    //wait left
                    if(dryThen[cur_cell-1]>cur_time)
                        cur_time = dryThen[cur_cell-1];
                        
                    //move left
                    cur_time++;
                    cur_cell--;
                }
                else{
                    //wait right
                    if(dryThen[cur_cell+1]>cur_time)
                        cur_time = dryThen[cur_cell+1];
                        
                    //move right
                    cur_time++;
                    cur_cell++;
                }
            }
            else if(cur_cell>0){
                //wait left
                if(dryThen[cur_cell-1] > cur_time)
                    cur_time = dryThen[cur_cell-1];
                    
                //move left
                cur_time++;
                cur_cell--;
            }
            else if(cur_cell<len-1){
                //wait right
                if(dryThen[cur_cell+1]>cur_time)
                    cur_time = dryThen[cur_cell+1];
                
                //move right
                cur_time++;
                cur_cell++;
            }
        }
        
        //step 2
        cur_time++;
    //    System.out.println("paint"+next_cell+",time="+cur_time);
        dryThen[next_cell]=cur_time+dryTime[next_cell];
        
        //step 3
        if(cur_time>=min_time){
            
        }
        else{
        //paint all the unpainted cell
            int i,count=0;
            for(i=0;i<dryThen.length;i++){
                //System.out.println(i);
                if(dryThen[i]==0){
                    paint(dryThen,dryTime,cur_cell,i,cur_time);
                    count++;    
                }
            }
            //log the new min_time
            if(count==0&&cur_time<min_time){
            //    System.out.println(cur_time);
                min_time = cur_time;
            }
        }
    
        //step 4
        dryThen[next_cell]=0;
    }
}