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diff --git a/out/report-cls06.pdf b/out/report-cls06.pdf
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diff --git a/report-cls06.tex b/report-cls06.tex
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+\documentclass[xelatex,a4paper,11pt,ja=standard]{bxjsarticle}
+
+\usepackage{tex/preamble}
+\usepackage{tex/simple-title}
+
+\reportauthor{柴田健琉}
+\reporttitle{情報処理2 - 前期第6回課題}
+\reportdate{2026年}{05月}{25日}
+\turnindate{2026年}{05月}{25日}
+
+\begin{document}
+    \simpletitle
+
+    \section{はじめに}
+
+    この課題のプログラムは以下の環境での動作が確認されている:
+
+    \begin{itemize}
+        \item {OS: NixOS 25.11 Xantusia, Linux 7.0.9 x86\_64}
+        \item {CC: GCC 15.2.0}
+        \item {CFLAGS: \texttt{-g -O1 -Wall -Wpedantic}}
+    \end{itemize}
+
+    \section{課題1}
+
+    入力した文字列\texttt{s}内に特定の文字\texttt{c}の出現回数を返す関数\texttt{str\_chnum}を作成する.
+
+    \lstinputlisting[language=C,title={課題1のプログラム}]{./src/cls06/a1.c}
+
+    \subsection{実行結果}
+
+    \begin{figure}[tbh]
+        \centering
+        \includegraphics[width=12cm]{./assets/cls06-a1.png}
+        \caption{課題1の実行結果}
+    \end{figure}
+
+    \section{課題2}
+
+    入力した文字列\texttt{s}を\texttt{n}回連続で出力するサブルーティーン\texttt{put\_stringn}を作成する.
+
+    \lstinputlisting[language=C,title={課題2のプログラム}]{./src/cls06/a2.c}
+
+    \subsection{実行結果}
+
+    \begin{figure}[tbh]
+        \centering
+        \includegraphics[width=12cm]{./assets/cls06-a2.png}
+        \caption{課題2の実行結果}
+    \end{figure}
+\end{document}
diff --git a/src/cls06/Makefile b/src/cls06/Makefile
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index 0000000..3dbc04e
--- /dev/null
+++ b/src/cls06/Makefile
@@ -0,0 +1,14 @@
+include ../common.mk
+
+PROJECT_NAME:=cls06
+
+TGTS:=$(patsubst %.c,%,$(wildcard *.c))
+
+all: $(TGTS)
+
+%: %.c
+	@mkdir -p $(BUILD_PATH)/$(PROJECT_NAME)
+	$(CC) $(CFLAGS) $^ -o $(BUILD_PATH)/$(PROJECT_NAME)/$@
+
+clean:
+	$(RM) -drf $(BUILD_PATH)/$(PROJECT_NAME)
diff --git a/src/cls06/a1.c b/src/cls06/a1.c
new file mode 100644
index 0000000..09f1057
--- /dev/null
+++ b/src/cls06/a1.c
@@ -0,0 +1,37 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define BUFF_SZ 256
+
+int str_chnum(const char s[], int c) {
+    int idx = 0;
+    int n = 0;
+    
+    while (s[idx] != '\0' && idx < BUFF_SZ) {
+        if (s[idx] == (char)c) {
+            n++;
+        }
+        idx++;
+    }
+
+    return n;
+}
+
+int main(void) {
+    char *buff = (char*)calloc(sizeof(char), BUFF_SZ);
+    char query = 0;
+
+    printf("Input String: ");
+    fgets(buff, BUFF_SZ, stdin);
+
+    printf("Input Search Character: ");
+    scanf("%c", &query);
+
+    int cnt = str_chnum(buff, query);
+
+    printf("Found %d \'%c\'\n", cnt, query, buff);
+
+    free(buff);
+
+    return 0;
+}
diff --git a/src/cls06/a2.c b/src/cls06/a2.c
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index 0000000..7aa92fe
--- /dev/null
+++ b/src/cls06/a2.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define BUFF_SZ 256
+
+void put_stringn(const char s[], int n) {
+    if (n < 0) return;
+
+    int idx = 0;
+
+    for (int i = 0; i < n; i++) {
+        idx = 0;
+        while (s[idx] != '\0' && idx < BUFF_SZ) {
+            if (s[idx] == '\n') {
+                idx++;
+                continue;
+            }
+            putchar(s[idx]);
+            idx++;
+        }
+    }
+
+    putchar('\0');
+}
+
+int main(void) {
+    char *buff = (char*)calloc(sizeof(char), BUFF_SZ);
+    int n = 0;
+
+    printf("Input String: ");
+    fgets(buff, BUFF_SZ, stdin);
+
+    printf("Input Repeat Num: ");
+    scanf("%d", &n);
+
+    put_stringn(buff, n);
+    putchar('\n');
+
+    free(buff);
+
+    return 0;
+}