Algorithm
Problem Name: 68. Text Justification
Given an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justified.
You should pack your words in a greedy approach; that is, pack as many words as you can in each line. Pad extra spaces ' ' when necessary so that each line has exactly maxWidth characters.
Extra spaces between words should be distributed as evenly as possible. If the number of spaces on a line does not divide evenly between words, the empty slots on the left will be assigned more spaces than the slots on the right.
For the last line of text, it should be left-justified, and no extra space is inserted between words.
Note:
- A word is defined as a character sequence consisting of non-space characters only.
- Each word's length is guaranteed to be greater than
0and not exceedmaxWidth. - The input array
wordscontains at least one word.
Example 1:
Input: words = ["This", "is", "an", "example", "of", "text", "justification."], maxWidth = 16 Output: [ "This is an", "example of text", "justification. " ]
Example 2:
Input: words = ["What","must","be","acknowledgment","shall","be"], maxWidth = 16 Output: [ "What must be", "acknowledgment ", "shall be " ] Explanation: Note that the last line is "shall be " instead of "shall be", because the last line must be left-justified instead of fully-justified. Note that the second line is also left-justified because it contains only one word.
Example 3:
Input: words = ["Science","is","what","we","understand","well","enough","to","explain","to","a","computer.","Art","is","everything","else","we","do"], maxWidth = 20 Output: [ "Science is what we", "understand well", "enough to explain to", "a computer. Art is", "everything else we", "do " ]
Constraints:
1 <= words.length <= 3001 <= words[i].length <= 20words[i]consists of only English letters and symbols.1 <= maxWidth <= 100words[i].length <= maxWidth
Code Examples
#1 Code Example with C Programming
Code -
C Programming
char *make_str1(char **words, int *lens, int x, int l, int width) {
char *s;
int i, j, k, num_of_space, rem_of_space;
s = malloc((width + 1) * sizeof(char));
//assert(s);
if (x > 1) {
num_of_space = (width - l) / (x - 1);
rem_of_space = (width - l) % (x - 1);
} else {
num_of_space = width - l;
rem_of_space = 0;
}
k = 0;
for (i = 0; i < x; i ++) {
strcpy(&s[k], words[i]);
k += lens[i];
for (j = 0; (i == 0 || i != x - 1) && j < num_of_space; j ++) {
s[k] = ' ';
k ++;
}
if (rem_of_space) {
s[k] = ' ';
k ++;
rem_of_space --;
}
}
s[k] = 0;
return s;
}
char *make_str2(char **words, int *lens, int x, int l, int width) {
char *s;
int i, k;
s = malloc(width * sizeof(char));
//assert(s);
k = 0;
for (i = 0; i < x; i ++) {
if (i) {
s[k] = ' ';
k ++;
}
strcpy(&s[k], words[i]);
k += lens[i];
}
while (k < width) {
s[k] = ' ';
k ++;
}
s[k] = 0;
return s;
}
char** fullJustify(char** words, int wordsSize, int maxWidth, int* returnSize) {
int *lens, sz, n, i, l, k;
char **p = NULL, *s;
int a, b;
sz = 10;
n = 0;
p = malloc(sz * sizeof(char *));
lens = malloc(wordsSize * sizeof(int));
//assert(p && lens);
k = 0; a = 0;
for (i = 0; i < wordsSize; i ++) {
l = strlen(words[i]);
//assert(l < = maxWidth);
lens[i] = l;
if (k + l + i - a > maxWidth) {
// form a line
s = make_str1(&words[a], &lens[a], i - a, k, maxWidth);
//printf("%s\n", s);
//free(s);
if (n == sz) {
sz *= 2;
p = realloc(p, sz * sizeof(char *));
//assert(p);
}
p[n ++] = s;
k = 0; a = i;
}
k += l;
}
s = make_str2(&words[a], &lens[a], i - a, k, maxWidth);
//printf("%s\n", s);
//free(s);
if (n == sz) {
sz *= 2;
p = realloc(p, sz * sizeof(char *));
//assert(p);
}
p[n ++] = s;
*returnSize = n;
free(lens);
return p;
}
Input
words = ["What","must","be","acknowledgment","shall","be"], maxWidth = 16
Output
[
"What must be",
"acknowledgment ",
"shall be "
]
#2 Code Example with C++ Programming
Code -
C++ Programming
class Solution {
public:
vector<string> fullJustify(vector<string>& words, int maxWidth) {
vector<string>res;
if(maxWidth == 0) return {""};
int i = 0, j = 0;
while(j != words.size()){
int len = -1;
while(j < words.size() && len + words[j].size() + 1 < = maxWidth)
len += words[j++].size() + 1;
int space = maxWidth - len + j - i - 1;
int k = i;
while(space){
words[k++] += " ";
space--;
if(j != words.size() && (k == j - 1 || k == j)) k = i;
if(j == words.size() && k == j) k = j - 1;
}
string line = "";
for(int l = i; l < j; l++)
line += words[l];
res.push_back(line>;
i = j;
}
return res;
}
};
Input
words = ["This", "is", "an", "example", "of", "text", "justification."], maxWidth = 16
Output
[
"This is an",
"example of text",
"justification. "
]
#3 Code Example with Java Programming
Code -
Java Programming
class Solution {
public List fullJustify(String[] words, int maxWidth) {
List list = new ArrayList<>();
int idx = 0;
int n = words.length;
while (idx < n) {
int count = 0;
int currLength = 0;
int oldIdx = idx;
int totalWordLength = 0;
while (idx < n && currLength + words[idx].length() <= maxWidth) {
count++;
currLength += words[idx].length() + 1;
totalWordLength += words[idx].length();
idx++;
}
StringBuilder sb = new StringBuilder();
// Left Justify
if (count == 1 || idx == n) {
while (oldIdx < idx) {
sb.append(words[oldIdx++]);
if (!words[oldIdx-1].endsWith(".") && oldIdx != idx) {
sb.append(" ");
}
}
while (sb.length() < maxWidth) {
sb.append(" ");
}
}
// Left & Right Justify
else {
int spacing = (maxWidth - totalWordLength) / (count - 1);
int extraSpacing = maxWidth - totalWordLength - spacing * (count - 1);
int tempIdx = oldIdx;
while (tempIdx < idx) {
sb.append(words[tempIdx++]);
if (tempIdx != idx) {
int totalSpace = spacing + (extraSpacing > 0 ? 1 : 0);
extraSpacing--;
for (int j = 0; j < totalSpace; j++) {
sb.append(" ");
}
}
}
}
list.add(sb.toString());
}
return list;
}
}
Input
words = ["This", "is", "an", "example", "of", "text", "justification."], maxWidth = 16
Output
[
"This is an",
"example of text",
"justification. "
]
#4 Code Example with Javascript Programming
Code -
Javascript Programming
const fullJustify = function(words, maxWidth) {
const res = []
let curRow = []
let numOfChars = 0
for (let w of words) {
if (numOfChars + w.length + curRow.length > maxWidth) {
for(let i = 0; i < maxWidth - numOfChars; i++) {
if(curRow.length === 1) {
curRow[0] += ' '
} else {
curRow[i % (curRow.length - 1)] += ' '
}
}
res.push(curRow.join(''))
curRow = []
numOfChars = 0
}
curRow.push(w)
numOfChars += w.length
}
const numOfSpace = maxWidth - numOfChars - (curRow.length - 1)
let tail = ''
for(let i = 0; i < numOfSpace; i++) tail += ' '
res.push(curRow.join(' ') + tail>
return res
};
Input
words = ["This", "is", "an", "example", "of", "text", "justification."], maxWidth = 16
Output
[
"This is an",
"example of text",
"justification. "
]
#5 Code Example with Python Programming
Code -
Python Programming
class Solution:
def fullJustify(self, words: List[str], maxWidth: int) -> List[str]:
res, used, s = [], 0, []
for i, w in enumerate(words):
if not s or len(w) + used + len(s) <= maxWidth:
used += len(w)
s += [w]
else:
if len(s) == 1:
res.append(s[0] + (maxWidth - used) * ' ')
else:
br = (maxWidth - used) // (len(s) - 1)
res.append(''.join((br + (i <= (maxWidth - used) % (len(s) - 1))) * ' ' + c for i, c in enumerate(s)).lstrip())
used, s = len(w), [w]
return res + [' '.join(c for c in s) + (maxWidth - used - len(s) + 1) * ' ']
Input
words = ["What","must","be","acknowledgment","shall","be"], maxWidth = 16
Output
[
"What must be",
"acknowledgment ",
"shall be "
]
#6 Code Example with C# Programming
Code -
C# Programming
using System.Collections.Generic;
using System.Text;
namespace LeetCode
{
public class _068_TextJustification
{
public IList < string> FullJustify(string[] words, int maxWidth)
{
var result = new List();
int start = 0, len = 0;
var builder = new StringBuilder();
for (int i = 0; i < words.Length; i++)
{
if (len + words[i].Length > maxWidth)
{
var space = maxWidth - len + (i - start);
builder.Clear();
for (int j = start; j < i; j++)
{
builder.Append(words[j]);
var tempSpace = j != i - 1
? space / (i - start - 1) + ((j - start < (space % (i - start - 1))) ? 1 : 0)
: maxWidth - builder.Length;
builder.Append(new string(' ', tempSpace));
}
result.Add(builder.ToString());
len = 0;
start = i;
}
len += words[i].Length + 1;
}
builder.Clear();
for (int j = start; j < words.Length; j++)
{
builder.Append(words[j]);
var tempSpace = j != words.Length - 1
? 1
: maxWidth - builder.Length;
builder.Append(new string(' ', tempSpace));
}
result.Add(builder.ToString());
return result;
}
}
}
Input
words = ["What","must","be","acknowledgment","shall","be"], maxWidth = 16
Output
[
"What must be",
"acknowledgment ",
"shall be "
]