public int compress(char[] chars) {

if (chars == null || chars.length <= 0) return 0;

if (chars.length == 1) return 1;

int i = 1;

int j = 1;

int count = 1;

char pre = chars[0];

while (j < chars.length) {

if (chars[j] == pre) {

count++;

j++;

} else {

if (count != 1) {

char[] nums = Integer.toString(count).toCharArray();

for (char n: nums) {

chars[i++] = n;

}

}

pre = chars[j];

count = 1;

j++;

chars[i] = pre;

i++;

}

}

if (count != 1) {

char[] nums = Integer.toString(count).toCharArray();

for (char n: nums) {

chars[i++] = n;

}

}

return i;

}

/**

public int compress2(char[] chars) {

int anchor = 0, write = 0;

for (int read = 0; read < chars.length; read++) {

if (read + 1 == chars.length || chars[read + 1] != chars[read]) {

chars[write++] = chars[anchor];

if (read > anchor) {

for (char c: ("" + (read - anchor + 1)).toCharArray()) {

chars[write++] = c;

}

}

anchor = read + 1;

}

}

return write;

}