剑指offer-问题4

野性酷女 2022-05-10 12:33 211阅读 0赞

package offer;
    
    /**
     * offer interview 4
     */
    public class Test04 {
    
        public static int replaceBlank(char[] string,int usedLength){
    
            if (null == string || string.length < usedLength){
                return -1;
            }
    
            int whiteCount = 0;
            for (int i = 0 ; i < usedLength ; i++){
                if (string[i] == ' '){
                    whiteCount++;
                }
            }
    
            int targetLength = whiteCount * 2 + usedLength;
            int temp = targetLength;
            if (targetLength > string.length){
                return -1;
            }
    
            if (0 == whiteCount){
                return usedLength;
            }
    
            usedLength--;
            targetLength--;
    
            while(usedLength >= 0 && usedLength < targetLength){
                if (string[usedLength] == ' '){
                    string[targetLength--] = '0';
                    string[targetLength--] = '2';
                    string[targetLength--] = '%';
                }else{
                    string[targetLength--] = string[usedLength];
                }
                usedLength--;
            }
            return temp;
        }
    
        public static void main(String[] args){
            char[] string = new char[50];
            string[0] = ' ';
            string[1] = 'e';
            string[2] = ' ';
            string[3] = ' ';
            string[4] = 'r';
            string[5] = 'e';
            string[6] = ' ';
            string[7] = ' ';
            string[8] = 'a';
            string[9] = ' ';
            string[10] = 'p';
            string[11] = ' ';
    
            int length = replaceBlank(string,12);
            System.out.println(new String (string,0,length));
        }
    
    }