diff --git a/agc011/Cargo.lock b/agc011/Cargo.lock
index be05307f..3b7cbbcb 100644
--- a/agc011/Cargo.lock
+++ b/agc011/Cargo.lock
@@ -4,16 +4,100 @@
 name = "agc011"
 version = "0.1.0"
 dependencies = [
+ "num",
  "proconio",
  "superslice",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
+[[package]]
+name = "num"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8536030f9fea7127f841b45bb6243b27255787fb4eb83958aa1ef9d2fdc0c36"
+dependencies = [
+ "num-bigint",
+ "num-complex",
+ "num-integer",
+ "num-iter",
+ "num-rational",
+ "num-traits",
+]
+
+[[package]]
+name = "num-bigint"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "090c7f9998ee0ff65aa5b723e4009f7b217707f1fb5ea551329cc4d6231fb304"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-complex"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6b19411a9719e753aff12e5187b74d60d3dc449ec3f4dc21e3989c3f554bc95"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-integer"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
+[[package]]
+name = "num-iter"
+version = "0.1.43"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d03e6c028c5dc5cac6e2dec0efda81fc887605bb3d884578bb6d6bf7514e252"
+dependencies = [
+ "autocfg",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-rational"
+version = "0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c000134b5dbf44adc5cb772486d335293351644b801551abe8f75c84cfa4aef"
+dependencies = [
+ "autocfg",
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+]
+
+[[package]]
+name = "num-traits"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "578ede34cf02f8924ab9447f50c28075b4d3e5b269972345e7e0372b38c6cdcd"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "0.4.30"
@@ -35,9 +119,9 @@ dependencies = [
 
 [[package]]
 name = "proconio-derive"
-version = "0.1.6"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fc2f2111a9562adf5ba291143c434818c908a05636c8a492a0a69ba4720a2c16"
+checksum = "8096c9313b401ca5bf09f93235fdf4fe6dbedc4f64e3968d2688bf89433a6738"
 dependencies = [
  "proc-macro2",
  "quote",
diff --git a/agc011/Cargo.toml b/agc011/Cargo.toml
index e4fe26ea..878a4820 100644
--- a/agc011/Cargo.toml
+++ b/agc011/Cargo.toml
@@ -1,11 +1,11 @@
 [package]
 name = "agc011"
 version = "0.1.0"
-authors = ["bouzuya <m@bouzuya.net>"]
 edition = "2018"
 
 # dependencies added to new project
 [dependencies]
+num = "=0.2.1"
 proconio = { version = "=0.3.6", features = ["derive"] }
 superslice = "=1.0.0"
 
diff --git a/agc011/src/bin/a.rs b/agc011/src/bin/a.rs
index 50e23b6c..5372d973 100644
--- a/agc011/src/bin/a.rs
+++ b/agc011/src/bin/a.rs
@@ -3,24 +3,24 @@ use proconio::input;
 fn main() {
     input! {
         n: usize,
-        c: usize,
+        capital_c: usize,
         k: usize,
         mut t: [usize; n],
     };
     t.sort();
 
-    let mut ans = 0;
-    let mut i_l = 0;
-    let mut i_r = 0;
-    while i_l < n {
-        while i_r + 1 < n && t[i_r + 1] <= t[i_l] + k {
-            i_r += 1;
-        }
-        ans += 1;
-        i_l += c;
-        if i_l > i_r {
-            i_l = i_r + 1;
+    let mut index = 0_usize;
+    let mut count = 0_usize;
+    while index < n {
+        let mut c = 0_usize;
+        let mut j = index;
+        while (j < n) && (t[j] <= t[index] + k) && (c < capital_c) {
+            c += 1;
+            j += 1;
         }
+        count += 1;
+        index = j;
     }
+    let ans = count;
     println!("{}", ans);
 }
diff --git a/agc011/src/bin/b.rs b/agc011/src/bin/b.rs
index 210c5992..0a3f4d9a 100644
--- a/agc011/src/bin/b.rs
+++ b/agc011/src/bin/b.rs
@@ -3,20 +3,20 @@ use proconio::input;
 fn main() {
     input! {
         n: usize,
-        mut a: [i64; n],
+        mut a: [usize; n],
     };
     a.sort();
-    let s = std::iter::once(0)
-        .chain(a.iter().scan(0, |acc, a_i| {
-            *acc += a_i;
+    let c = std::iter::once(0)
+        .chain(a.iter().scan(0, |acc, &i| {
+            *acc += i;
             Some(*acc)
         }))
-        .collect::<Vec<_>>();
-    let c = a
-        .iter()
-        .zip(s.iter())
-        .rposition(|(&a_i, &s_i)| s_i * 2 < a_i)
+        .collect::<Vec<usize>>();
+    let count = a
+        .into_iter()
+        .zip(c.into_iter())
+        .rposition(|(a_i, c_i)| a_i > c_i * 2)
         .unwrap_or(0);
-    let ans = n - c;
+    let ans = n - count;
     println!("{}", ans);
 }
diff --git a/agc011/src/bin/c.rs b/agc011/src/bin/c.rs
index 101ebb15..2a9506c8 100644
--- a/agc011/src/bin/c.rs
+++ b/agc011/src/bin/c.rs
@@ -1,5 +1,4 @@
-use proconio::input;
-use proconio::marker::Usize1;
+use proconio::{input, marker::Usize1};
 
 fn main() {
     input! {
diff --git a/agc011/src/bin/d.rs b/agc011/src/bin/d.rs
index 101ebb15..2a9506c8 100644
--- a/agc011/src/bin/d.rs
+++ b/agc011/src/bin/d.rs
@@ -1,5 +1,4 @@
-use proconio::input;
-use proconio::marker::Usize1;
+use proconio::{input, marker::Usize1};
 
 fn main() {
     input! {
diff --git a/agc011/src/bin/e.rs b/agc011/src/bin/e.rs
index 101ebb15..2a9506c8 100644
--- a/agc011/src/bin/e.rs
+++ b/agc011/src/bin/e.rs
@@ -1,5 +1,4 @@
-use proconio::input;
-use proconio::marker::Usize1;
+use proconio::{input, marker::Usize1};
 
 fn main() {
     input! {
diff --git a/agc011/src/bin/f.rs b/agc011/src/bin/f.rs
index 101ebb15..2a9506c8 100644
--- a/agc011/src/bin/f.rs
+++ b/agc011/src/bin/f.rs
@@ -1,5 +1,4 @@
-use proconio::input;
-use proconio::marker::Usize1;
+use proconio::{input, marker::Usize1};
 
 fn main() {
     input! {