update gitignore. update compile.sh

contests/5contest/1.cpp

@@ -2,20 +2,18 @@
 #include <vector>
 #include <algorithm>
 
-bool comp(unsigned int a, unsigned int b) {
+int cnt_bit(unsigned int a) {
     int res1 = 0;
     while (a != 0) {
         res1 += a & 1;
         a = a >> 1;
     }
 
-    int res2 = 0;
-    while (b != 0) {
-        res2 += b & 1;
-        b = b >> 1;
-    }
+    return res1;
+}
 
-    return res1 < res2;
+bool comp(unsigned int a, unsigned int b) {
+    return cnt_bit(a) < cnt_bit(b);
 }
 
 

contests/5contest/2.cpp

@@ -11,12 +11,12 @@ int main() {
         mp[name].push_back(grade);
     }
 
-    for (auto x : mp) {
+    for (auto& x : mp) {
         std::cout << x.first << " ";
 
         double tmp = 0;
         int n = 0;
-        for (auto i : x.second) {
+        for (auto& i : x.second) {
             tmp += i;
             ++n;
         }

contests/5contest/4.cpp

@@ -18,7 +18,7 @@ int main() {
         mp[std::make_pair(r, c)] %= mod;
     }
 
-    for (auto x : mp) {
+    for (auto& x : mp) {
         if (x.second) std::cout << x.first.first << " " << x.first.second << " " << x.second << std::endl;
     }