天题系列： Candy

    public int candy(int[] ratings) {
        if(ratings == null) return 0;
        int len = ratings.length;
        int res = 0;
        if(len==1) return 1;
        int [] lf = new int[len];
        int [] rt = new int[len];
        lf[0]=1;
        for(int i=1;i<len;i++){
            if(ratings[i]>ratings[i-1]){
                lf[i] = lf[i-1]+1;
            }else
                lf[i] = 1;
        }
        rt[len-1] = lf[len-1];
        for(int j=len-2;j>=0;j--){
            if(ratings[j]>ratings[j+1]){
                rt[j] = rt[j+1]+1;
            }else  
                rt[j]=1;
        }
        for(int i=0;i<len;i++){
            res+=Math.max(rt[i],lf[i]);
        }
        return res;
    }