力扣刷题：
- 重新排列数组：
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* shuffle(int* nums, int numsSize, int n, int* returnSize){
if (numsSize==1)
{
*returnSize = 1;
return nums;
}
int *res = (int *)malloc(sizeof(int) * numsSize);
int i=0;
int j=0;
while (j!=numsSize)
{
res[j] = nums[i];
res[j+1] = nums[i+(numsSize/2)];
i++;
j+=2;
}
*returnSize = numsSize;
return res;
}
- 数组串联:
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* getConcatenation(int* nums, int numsSize, int* returnSize){
int *res = (int *)malloc(sizeof(int) * (numsSize * 2));
for (int i=0;i<numsSize;i++)
{
res[i] = nums[i];
res[i+numsSize] = nums[i];
}
*returnSize = numsSize * 2;
return res;
}
- 基于排列构建数组:
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* buildArray(int* nums, int numsSize, int* returnSize){
int *res = (int *)malloc(sizeof(int) * numsSize);
for (int i=0;i<numsSize;i++)
{
res[i] = nums[nums[i]];
}
*returnSize = numsSize;
return res;
}
- 一维数组的动态和:
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* runningSum(int* nums, int numsSize, int* returnSize){
if (numsSize == 1){
*returnSize = 1;
return nums;
}
int *res = (int *)malloc(sizeof(int) * numsSize);
for (int i=0;i<numsSize;i++)
{
res[i] = sumNum(i, nums);
}
*returnSize = numsSize;
return res;
}
int sumNum(int n, int *nums)
{
int sum = 0;
for(int i=0;i<=n;i++)
{
sum += nums[i];
}
return sum;
}
剑指 Offer 58 - II. 左旋转字符串
char* reverseLeftWords(char* s, int n){
int len = strlen(s);
char *res = (char *)malloc(sizeof(char)*(len+1));
for (int i=0;i<len;++i)
{
res[i] = s[(i+n)%len];
}
res[len] = '\0';
return res;
}
- IP 地址无效化
char * defangIPaddr(char * address){
char* res = (char *)malloc(sizeof(char) * 30);
int returnSize = 0;
for (int i=0;address[i];++i)
{
if (address[i] == '.')
{
res[returnSize++] = '[';
res[returnSize++] = '.';
res[returnSize++] = ']';
}else{
res[returnSize++] = address[i];
}
}
res[returnSize] = '\0';
return res;
}
剑指 Offer 05. 替换空格
char* replaceSpace(char* s){
char *ans = (char *)malloc(sizeof(char) * strlen(s) * 3 + 1);
int i = 0;
while (*s) {
if (*s == ' ') {
ans[i++] = '%';
ans[i++] = '2';
ans[i++] = '0';
} else {
ans[i++] = *s;
}
s++;
}
ans[i] = 0;
return ans;
}
- 有多少小于当前数字的数字
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* smallerNumbersThanCurrent(int* nums, int numsSize, int* returnSize){
int *res = (int *)malloc(sizeof(int) * numsSize);
for (int i=0;i<numsSize;i++)
{
res[i] = minSum(nums[i], nums, numsSize);
}
*returnSize = numsSize;
return res;
}
int minSum(int n, int *nums, int numsSize)
{
int res = 0;
for (int i=0;i<numsSize;i++)
{
if (nums[i] < n) res++;
}
return res;
}
剑指 Offer 17. 打印从1到最大的n位数
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* printNumbers(int n, int* returnSize){
int max = powSum(10, n) - 1;
int *res = (int *)malloc(sizeof(int) * max);
for (int i=0;i<max;i++)
{
res[i] = i+1;
}
*returnSize = max;
return res;
}
int powSum(int x, int y)
{
int res = 1;
for (int i=0;i<y;i++)
{
res *= x;
}
return res;
}
- 按既定顺序创建目标数组
/**
* Note: The returned array must be malloced, assume caller calls free().
*/
int* createTargetArray(int* nums, int numsSize, int* index, int indexSize, int* returnSize){
int len = 0;
int *res = (int *)malloc(sizeof(int) * numsSize);
for (int i=0;i<numsSize;++i)
{
for (int j=len;j>index[i];--j)
{
/*插入操作，也可以单独封装函数*/
res[j] = res[j-1];
}
res[index[i]] = nums[i];
++len;
}
*returnSize = len;
return res;
}