✅ 主要成分 map 实现

take-most-space-element/main.cc

@@ -0,0 +1,33 @@
+#include <unordered_map>
+using namespace std;
+
+int read() {
+  int x = 0, w = 1;
+  char ch = 0;
+  while (ch < '0' || ch > '9') {
+    if (ch == '-')
+      w = -1;
+    ch = getchar();
+  }
+  while (ch >= '0' && ch <= '9') {
+    x = x * 10 + (ch - '0');
+    ch = getchar();
+  }
+  return x * w;
+}
+
+int main() {
+  int n = read();
+  unordered_map<int, int> u;
+  for (int i = 0; i < n; i++) {
+    int val = read();
+    u[val]++;
+  }
+  for (const auto &[key, value] : u) {
+    if (value >= n / 2) {
+      printf("%d\n", key);
+      return 0;
+    }
+  }
+  printf("No\n");
+}