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Sum Strings as Numbers/main.cpp

@@ -0,0 +1,53 @@
+#include <string>
+#include <vector>
+#include <algorithm>
+#include <iostream>
+
+std::vector<std::string> sort_size(std::string &a, std::string &b){
+    if(a.size() <= b.size()){
+        return {a, b};
+    } else {
+        return {b, a};
+    }
+}
+
+void pad_zeros(std::string &input, int zeros_to_pad){
+    input.insert(0, zeros_to_pad, '0');
+}
+
+std::string sum_strings(std::string a, std::string b) {
+    a.erase(0, std::min(a.find_first_not_of('0'), a.size()-1));
+    b.erase(0, std::min(b.find_first_not_of('0'), b.size()-1));
+    auto shortest = sort_size(a, b);
+    int size_diff = abs(a.size() - b.size());
+
+    pad_zeros(shortest[0], size_diff);
+
+    int overflow = 0;
+    char insert;
+    std::string result;
+    for(int i=shortest[0].size()-1; i>=0; i--){
+        int val1 = shortest[1][i] - '0';
+        int val2 = shortest[0][i] - '0';
+        int temp = val1 + val2 + overflow;
+        if(temp>9){
+            overflow = temp / 10;
+            insert = std::to_string(temp)[1];
+        } else {
+            overflow = 0;
+            insert = std::to_string(temp)[0];
+        }
+        result.insert(0, 1, insert);
+    }
+
+    if(overflow > 0)
+        result.insert(0, std::to_string(overflow));
+
+    return result;
+}
+
+int main(){
+    std::string test1 = "99";
+    std::string test2 = "2";
+    std::cout << sum_strings(test1, test2);
+}