Fast way to read integers in I/O intensive problems

Author: coderick14

readint.cpp

@@ -0,0 +1,46 @@
+// a code snippet to read integers and long long integers faster
+#include <bits/stdc++.h>
+#define ll long long
+using namespace std;
+
+#ifndef ONLINE_JUDGE
+#define gc getchar
+#define pc putchar
+#else
+#define gc getchar_unlocked
+#define pc putchar_unlocked
+#endif
+
+int read_int() {
+    char c = gc();
+    while((c < '0' || c > '9') && c != '-') c = gc();
+    int ret = 0, neg = 0;
+    if (c == '-') neg = 1, c = gc();
+    while(c >= '0' && c <= '9') {
+        ret = 10 * ret + c - 48;
+        c = gc();
+    }
+    return neg ? -ret : ret;
+}
+
+ll read_ll() {
+    char c = gc();
+    while((c < '0' || c > '9') && c != '-') c = gc();
+    ll ret = 0;
+    int neg = 0;
+    if (c == '-') neg = 1, c = gc();
+    while(c >= '0' && c <= '9') {
+        ret = 10 * ret + c - 48;
+        c = gc();
+    }
+    return neg ? -ret : ret;
+}
+
+int main() {
+    int n;
+    ll k;
+    n = read_int();
+    k = read_ll();
+    cout<<"n = "<<n<<" k = "<<k<<"\n";
+    return 0;
+}