Pointers

pointer/.vscode/settings.json

@@ -1,3 +1,3 @@
 {
-    "markdown.validate.enabled": true
+    "markdown.validate.enabled": false
 }

pointer/setup/code-runners.ts

@@ -0,0 +1,57 @@
+import { defineCodeRunnersSetup } from '@slidev/types'
+
+export default defineCodeRunnersSetup(() => {
+  return {
+    async c(code) {
+      const JUDGE0_API = "http://localhost:2358/submissions?base64_encoded=true&wait=true"
+
+      // Matches "// input: {value}" anywhere in the line
+      const inputRegex = /\/\/\s*input:\s*([^\r\n]+)/gi
+      const matches = [...code.matchAll(inputRegex)]
+
+      // Join all found inputs with a newline for Judge0's stdin
+      const stdin = matches.map(m => m[1].trim()).join('\n')
+
+      const body = {
+        source_code: btoa(code),
+        language_id: 50,
+        stdin: btoa(stdin),
+      }
+
+      try {
+        const response = await fetch(JUDGE0_API, {
+          method: "POST",
+          headers: { "Content-Type": "application/json" },
+          body: JSON.stringify(body),
+        })
+
+        const result = await response.json()
+
+        // Decode results from Judge0 (Base64)
+        const output = result.stdout ? atob(result.stdout) : ''
+        const error = result.stderr ? atob(result.stderr) : ''
+        const compileErr = result.compile_output ? atob(result.compile_output) : ''
+
+        const text = output || error || compileErr || "Program executed (no output)."
+
+        return {
+          // Wrap in <pre> tag to ensure newlines are preserved
+          html: `<pre style="margin: 0; white-space: pre-wrap; word-wrap: break-word;" class="${
+            result.stdout ? 'text-green-400' : 'text-red-400'
+          }">${escapeHtml(text)}</pre>`,
+        }
+      } catch (e) {
+        return {
+          html: `<pre style="margin: 0; white-space: pre-wrap;" class="text-red-500 font-bold">Error connecting to Judge0: ${escapeHtml(e.message)}</pre>`,
+        }
+      }
+    },
+  }
+})
+
+// Helper function to escape HTML to prevent XSS
+function escapeHtml(text: string): string {
+  const div = document.createElement('div')
+  div.textContent = text
+  return div.innerHTML
+}

pointer/slides.md

@@ -307,13 +307,309 @@ int main(){
 <!-- baki ja janar, pore janbi usage dekhle. -->
 
 ---
-title: pointer to pointer
+layout: section
 ---
 
+# pointer to pointer
+
+---
+title: pointer to pointer visual
+---
+
+<v-switch>
+<template #0>
+
+```mermaid
+flowchart RL
+
+subgraph 1a[0x1003]
+direction TB
+1v[x = 5]
+1t[int]
+
+1v ~~~ 1t
+end
+```
+</template>
+<template #1>
+
+
+```mermaid
+flowchart LR
+
+subgraph 1a[0x1003]
+direction TB
+1v[x = 5]
+1t[int]
+
+1v ~~~ 1t
+end
+style 1a stroke:#fab387, stroke-width:3px
+
+subgraph 2a[0x1002]
+direction TB
+2v[p = 0x1003]
+2t[int*]
+
+2v ~~~ 2t
+end
+
+1a ~~~ 2a
+
+2a p3@--> 1a
+
+p3@{animate: true}
+```
+
+</template>
+<template #2>
+
+```mermaid
+flowchart LR
+
+subgraph 1a[0x1003]
+direction TB
+1v[x = 5]
+1t[int]
+
+1v ~~~ 1t
+end
+style 1a stroke:#fab387, stroke-width:3px
+
+subgraph 2a[0x1002]
+direction TB
+2v[p = 0x1003]
+2t[int*]
+
+2v ~~~ 2t
+end
+
+subgraph 3a[0x1001]
+direction TB
+3v[q = 0x1002]
+3t[int**]
+
+3v ~~~ 3t
+end
+
+1a ~~~ 2a ~~~ 3a
+
+3a p2@--> 2a p3@--> 1a
+
+p2@{animate: true}
+p3@{animate: true}
+```
+
+</template>
+<template #3>
+
+```mermaid
+flowchart RL
+
+subgraph 1a[0x1003]
+direction TB
+1v[x = 5]
+1t[int]
+
+1v ~~~ 1t
+end
+style 1a stroke:#fab387, stroke-width:3px
+
+subgraph 2a[0x1002]
+direction TB
+2v[p = 0x1003]
+2t[int*]
+
+2v ~~~ 2t
+end
+
+subgraph 3a[0x1001]
+direction TB
+3v[q = 0x1002]
+3t[int**]
+
+3v ~~~ 3t
+end
+
+subgraph 4a[0x1004]
+direction TB
+4v[r = 0x1001]
+4t[int***]:::hidden
+
+4v ~~~ 4t
+end
+
+4a ~~~ 1a ~~~ 2a ~~~ 3a
+
+3a p2@--> 2a p3@--> 1a
+
+p2@{animate: true}
+p3@{animate: true}
+```
+</template>
+<template #4>
+
+```mermaid
+flowchart RL
+
+subgraph 1a[0x1003]
+direction TB
+1v[x = 5]
+1t[int]
+
+1v ~~~ 1t
+end
+style 1a stroke:#fab387, stroke-width:3px
+
+subgraph 2a[0x1002]
+direction TB
+2v[p = 0x1003]
+2t[int*]
+
+2v ~~~ 2t
+end
+
+subgraph 3a[0x1001]
+direction TB
+3v[q = 0x1002]
+3t[int**]
+
+3v ~~~ 3t
+end
+
+subgraph 4a[0x1004]
+direction TB
+4v[r = 0x1001]
+4t[int***]
+
+4v ~~~ 4t
+end
+
+4a ~~~ 1a ~~~ 2a ~~~ 3a
+
+4a p1@--> 3a p2@--> 2a p3@--> 1a
+
+p1@{animate: true}
+p2@{animate: true}
+p3@{animate: true}
+```
+</template>
+</v-switch>
+
+---
+title: example pointer to pointer
+---
+
+```c {monaco-run}
+#include<stdio.h>
+int main(){
+  int x = 5; 
+  int* p = &x; // adress of x -> p
+  *p = 6; // change value of address inside p to 5
+  int** q = &p; // address of p -> q
+  int*** r = &q; // adress of q -> r
+}
+```
+
+<!-- 
+1. *p.
+2. *q
+3. *(*q)
+4. *(*r)
+5. *(*(*r))
+
+6. ***r = 10; print value of x
+7. **q = *p + 2; x=?
+-->
+
+
 ---
 title: pointer as function argument
 ---
 
+# pointer as function argument
+
+- call by value
+- call by reference
+
+````md magic-move
+```c
+#include<stdio.h>
+int increment(int a){
+  a = a + 1; // 11
+}
+int main(){
+  int a = 10;
+  increment(a); // 10
+  print("a = %d\n", a); // 10
+}
+```
+```c
+#include<stdio.h>
+int increment(int a){
+  a = a + 1; // 11
+  return a;
+}
+int main(){
+  int a = 10;
+  increment(a); // 10
+  print("a = %d\n", a); // 10
+}
+```
+```c
+#include<stdio.h>
+int increment(int a){
+  a = a + 1; // 11
+  return a;
+}
+int main(){
+  int a = 10;
+  a = increment(a); // 11
+  print("a = %d\n", a); // 11
+}
+```
+```c
+#include<stdio.h>
+int increment(int a){
+  a = a + 1; // 11
+}
+int main(){
+  int a = 10;
+  increment(a); // 10
+  print("a = %d\n", a); // 10
+}
+```
+```c
+#include<stdio.h>
+int increment(int a){
+  a = a + 1; // 11
+}
+int main(){
+  int a = 10;
+  increment(&a); // (0x1003)
+  print("a = %d\n", a); // 10
+}
+```
+```c
+#include<stdio.h>
+int increment(int* a){
+  *a = *a + 1; // *(0x1003) + 1
+}
+int main(){
+  int a = 10;
+  increment(&a); // (0x1003)
+  print("a = %d\n", a); // 11
+}
+```
+````
+
+<!-- 
+1. it copy the value, doent move the value.
+2. if we wanted change, we have to return, 
+3. and assigned the returned value
+3. we can pass the pointer. if we want direct.
+-->
+
 ---
 title: pointers and arrays
 ---