leetcode/FourSum.java at master · mengli/leetcode · GitHub

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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}
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importjava.util.ArrayList;
importjava.util.Arrays;

/**
 * Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d =
 * target?
 *
 * <p>Find all unique quadruplets in the array which gives the sum of target.
 *
 * <p>Note:
 *
 * <p>Elements in a quadruplet (a,b,c,d) must be in non-descending order. (ie, a <= b <= c <= d) The
 * solution set must not contain duplicate quadruplets.
 *
 * <p>For example, given array S = {1 0 -1 0 -2 2}, and target = 0.
 *
 * <p>A solution set is: (-1, 0, 0, 1) (-2, -1, 1, 2) (-2, 0, 0, 2)
 */
publicclassFourSum {
publicArrayList<ArrayList<Integer>> fourSum(int[] num, inttarget) {
ArrayList<ArrayList<Integer>> ret = newArrayList<ArrayList<Integer>>();
Arrays.sort(num);
intlength = num.length;
for (inti = 0; i < length - 3; i++) {
if (i > 0 && num[i] == num[i - 1]) continue;
for (intj = i + 1; j < length - 2; j++) {
if (j > i + 1 && num[j] == num[j - 1]) continue;
intl = j + 1;
intr = length - 1;
while (l < r) {
intdelta = num[i] + num[j] + num[l] + num[r] - target;
if (delta == 0) {
if (l > j + 1 && num[l] == num[l - 1]) {
l++;
continue;
 }
if (r < length - 1 && num[r] == num[r + 1]) {
r--;
continue;
 }
ArrayList<Integer> item = newArrayList<Integer>();
item.add(num[i]);
item.add(num[j]);
item.add(num[l]);
item.add(num[r]);
ret.add(item);
l++;
r--;
 } elseif (delta < 0) {
l++;
 } else {
r--;
 }
 }
 }
 }
returnret;
 }
}