ABC 048, finished all with help of editorial

atcoder/beginner_contests/abc048/src/bin/a.rs

@@ -0,0 +1,11 @@
+use proconio::input;
+
+fn main(){
+    input!{
+        _atcoder: String,
+        s: String,
+        _contest: String,
+    };
+
+    println!("A{}C", s.chars().next().unwrap());
+}

atcoder/beginner_contests/abc048/src/bin/b.rs

@@ -0,0 +1,21 @@
+use proconio::input;
+
+fn f(n: i64, x: i64) -> i64 {
+    if n == -1 {
+        0
+    } else {
+        n / x + 1
+    }
+}
+
+fn main(){
+    input!{
+        a: i64,
+        b: i64,
+        x: i64,
+    };
+
+    let result = f(b, x) - f(a - 1, x);
+
+    println!("{}", result);
+}

atcoder/beginner_contests/abc048/src/bin/c.rs

@@ -0,0 +1,25 @@
+use proconio::input;
+
+fn main(){
+    input!{
+        n: u64,
+        x: u64,
+        mut a: [u64; n],
+    };
+
+    let mut result = 0;
+    for i in 0..=((n-2) as usize) {
+        if a[i] + a[i+1] > x {
+            let dif = a[i] + a[i+1] - x;
+            if dif > a[i+1] {
+                a[i] -= dif - a[i+1];
+                a[i+1] = 0;
+            } else {
+                a[i+1] -= dif;
+            }
+            result += dif;
+        }
+    }
+
+    println!("{}", result);
+}

atcoder/beginner_contests/abc048/src/bin/d.rs

@@ -0,0 +1,13 @@
+use proconio::input;
+
+fn main(){
+    input!{
+        s: String,
+    };
+
+    if (s.len() % 2 == 0) ^ (s.chars().next().unwrap() == s.chars().last().unwrap()) {
+        println!("Second");
+    } else {
+        println!("First");
+    }
+}