2016/12/10 leetcode1:Summary Ranges

这是Array里的第一题。题意是找出排序好的数组的数字范围集合。

记录的知识点：

1,  c++中将数字转化为字符串

stringstream ss;

ss<<num

string tem = num.str();

2,  vector初始化，添加元素

vector<string> vecStr;

string tem;

vecStr.push_back(tem);

3, 遍历vector

vector<string>::iterator iter;

for(iter = vecStr.begin(); iter != vecStr.end(); iter++){

　　cout<< *iter;

}

这道题目的代码如下：

vector<string> summaryRanges(vector<int>& nums) {

int n = (int)nums.size();

vector<string> rangeStr;

int i = 0,j = 0;

while (j  <= n - 1) {

if (nums[j]+1 != nums[j+1]) {

string tem ;

if (i != j ) {

stringstream lefts ;

lefts << nums[i];

tem = lefts.str();

tem = tem + "->";

stringstream rights ;

rights << nums[j];

tem = tem + rights.str();

}else{

stringstream lefts ;

lefts << nums[i];

tem = lefts.str();

}

rangeStr.push_back(tem);

i = j+1;

}

j++;

}

if (i < n ) {

if ( i+1 == j) {

stringstream lefts ;

lefts << nums[i];

rangeStr.push_back(lefts.str());

}else{

string tem ;

stringstream lefts ;

lefts << nums[i];

tem = lefts.str();

tem = tem + "->";

stringstream rights ;

rights << nums[j-1];

tem = tem + rights.str();

rangeStr.push_back(tem);

}

}

return rangeStr;

}