solved some problems.

Author: coderfive

165.Compare Version Numbers/coderfive/165.cc

@@ -0,0 +1,44 @@
+#include <string>
+#include <iostream>
+using std::string;
+
+class Solution {
+public:
+    int compareVersion(string v1, string v2) {
+        std::string::size_type b1 = 0, b2 = 0;
+        std::string::size_type n1, n2;
+        while (b1 < v1.size() || b2 < v2.size()) {
+            if (b1 < v1.size())
+                n1 = std::stoi(v1.substr(b1));
+            else
+                n1 = 0;
+            if (b2 < v2.size())
+                n2 = std::stoi(v2.substr(b2));
+            else
+                n2 = 0;
+            if (n1 < n2) return -1;
+            else if (n1 > n2) return 1;
+            b1 = v1.find('.', b1);
+            b2 = v2.find('.', b2);
+            if (b1 == std::string::npos) {
+                b1 = v1.size();
+            }
+            else {
+                b1++;
+            }
+            if (b2 == std::string::npos) {
+                b2 = v2.size();
+            }
+            else {
+                b2++;
+            }
+        }
+        return 0;
+    }
+};
+
+int main() {
+    std::cout << Solution().compareVersion("1.3", "1.4") << std::endl;
+
+    return 0;
+}

166.Fraction to Recurring Decimal/coderfive/166.cc

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+#include <string>
+#include <algorithm>
+#include <iterator>
+#include <iostream>
+#include <vector>
+#include <sstream>
+using std::string;
+
+class Solution {
+public:
+    string fractionToDecimal(int arg_num, int arg_den) {
+        long long numerator = arg_num, denominator = arg_den;
+        std::ostringstream buf;
+        if ((numerator < 0 && denominator > 0) || (numerator > 0 && denominator < 0))
+            buf << '-';
+        numerator = std::abs(numerator);
+        denominator = std::abs(denominator);
+        long long d = numerator/denominator;
+        numerator %= denominator;
+        buf << d;
+        if (numerator != 0)
+            buf << '.';
+        else
+            return buf.str();
+        std::vector<int> num;
+        std::vector<int> div;
+        while (numerator != 0) {
+            auto it = std::find(num.begin(), num.end(), numerator);
+            if (it != num.end()) {
+                auto i = it-num.begin();
+                std::copy(div.begin(), div.begin()+i, std::ostream_iterator<int>(buf, ""));
+                buf << '(';
+                std::copy(div.begin()+i, div.end(), std::ostream_iterator<int>(buf, ""));
+                buf << ')';
+                return buf.str();
+            }
+            num.push_back(numerator);
+            numerator *= 10;
+            d = numerator/denominator;
+            div.push_back(d);
+            numerator %= denominator;
+        }
+        std::copy(div.begin(), div.end(), std::ostream_iterator<int>(buf, ""));
+        return buf.str();
+    }
+};
+
+
+int main() {
+    std::cout << Solution().fractionToDecimal(1, 3) << std::endl
+              << Solution().fractionToDecimal(1, 2) << std::endl
+              << Solution().fractionToDecimal(2, 1) << std::endl
+              << Solution().fractionToDecimal(-2147483648, -1) << std::endl;
+
+    return 0;
+}

168.Excel Sheet Column Title/coderfive/168.cc

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+class Solution {
+public:
+    string convertToTitle(int n) {
+        string res;
+        int t;
+        do {
+            t = n%26;
+            if (t == 0) {
+                res.push_back('Z');
+                n -= 26;
+            }
+            else {
+                n -= t;
+                res.push_back(t-1+'A');
+            }
+            n /= 26;
+        } while (n);
+        std::reverse(res.begin(), res.end());
+        return res;
+    }
+};

169.Majority Element/coderfive/169.cc

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+class Solution {
+public:
+    int majorityElement(vector<int>& nums) {
+        int res = nums[0];
+        int count = 0;
+        for (auto n : nums) {
+            if (n == res) count++;
+            else count--;
+            if (count <= 0) {
+                res = n;
+                count = 1;
+            }
+        }
+        return res;
+    }
+};