add 3 exercises

data/2.dailycode中阶/1.cpp/19.exercises/solution.md

 # 字符图形输出
 
 编程实现把输入任意整数n后，可打印出n行三角字符阵列图形。例如，输入整数5时，程序运行结果如下：
+
+```json
 ENTER A NUMBER：5<回车>
 A  C  F  J  O
 B  E  I  N
 D  H  M
 G  L
 K
+```
+
+以下程序实现了这一功能，请你填补空白处内容：
+
+```cpp
+#include <iostream>
+using namespace std;
+char a[100][100];
+int main()
+{
+    char c = 'A';
+    int n = 5;
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = i; j >= 0; j--)
+        {
+            _______________;
+        }
+    }
+    for (int i = 0; i < n; i++)
+    {
+        for (int j = 0; j < n - i; j++)
+        {
+            cout << a[i][j] << " ";
+        }
+        cout << endl;
+    }
+}
+```
 
 ## template
 
 ```cpp
- #include <iostream>
+#include <iostream>
 using namespace std;
 char a[100][100];
 int main()
@@ -39,7 +70,7 @@ int main()
 ## 答案
 
 ```cpp
-
+a[j][i - j] = c++;
 ```
 
 ## 选项
@@ -47,17 +78,17 @@ int main()
 ### A
 
 ```cpp
-
+a[j][i] = c++;
 ```
 
 ### B
 
 ```cpp
-
+a[j - 1][i - j] = c++;
 ```
 
 ### C
 
 ```cpp
-
+a[j][i - 1] = c++;
 ```
\ No newline at end of file

data/2.dailycode中阶/1.cpp/20.exercises/solution.md

@@ -2,6 +2,48 @@
 
 <p>如何在一亿位整数组成的字符串中找到最长的递增数字字符串&#xff1f;</p>
 
+以下程序实现了这一功能，请你填补空白处内容：
+
+```cpp
+#include <stdio.h>
+#include <string.h>
+#define MAX_SIZE 100000
+int main()
+{
+    char buf[MAX_SIZE] = {0};
+    int i = 0, len = 0, index = 0;
+    char maxbuf[12] = {0};
+    char maxbuf2[12] = {0};
+    int maxlen = 0;
+    gets(buf);
+    len = strlen(buf);
+    maxbuf2[0] = buf[0];
+    i = 1;
+    index = 1;
+    while (i < len)
+    {
+        if (buf[i] > buf[i - 1])
+        {
+            maxbuf2[index] = buf[i];
+            index++;
+        }
+        else
+        {
+            _________________;
+        }
+        i++;
+    }
+    if (index > maxlen)
+    {
+        maxlen = index;
+        strcpy(maxbuf, maxbuf2);
+        maxbuf[index] = '\0';
+    }
+    printf("最大串长度:%d,字符串:%s\n", maxlen, maxbuf);
+    return 0;
+}
+```
+
 ## template
 
 ```cpp
@@ -11,7 +53,7 @@
 int main()
 {
     char buf[MAX_SIZE] = {0};
-	int i = 0,len = 0,index = 0;
+    int i = 0, len = 0, index = 0;
     char maxbuf[12] = {0};
     char maxbuf2[12] = {0};
     int maxlen = 0;
@@ -20,22 +62,24 @@ int main()
     maxbuf2[0] = buf[0];
     i = 1;
     index = 1;
-	while(i < len)
+    while (i < len)
     {
-		if (buf[i] > buf[i-1])
+        if (buf[i] > buf[i - 1])
         {
             maxbuf2[index] = buf[i];
             index++;
-		}else
+        }
+        else
         {
             if (index > maxlen)
             {
                 maxlen = index;
-				strcpy(maxbuf,maxbuf2);
+                strcpy(maxbuf, maxbuf2);
                 maxbuf[index] = '\0';
                 maxbuf2[0] = buf[i];
                 index = 1;
-			}else
+            }
+            else
             {
                 maxbuf2[0] = buf[i];
                 index = 1;
@@ -46,10 +90,10 @@ int main()
     if (index > maxlen)
     {
         maxlen = index;
-		strcpy(maxbuf,maxbuf2);
+        strcpy(maxbuf, maxbuf2);
         maxbuf[index] = '\0';
     }
-	printf("最大串长度:%d,字符串:%s\n",maxlen,maxbuf);
+    printf("最大串长度:%d,字符串:%s\n", maxlen, maxbuf);
     return 0;
 }
 ```
@@ -57,7 +101,19 @@ int main()
 ## 答案
 
 ```cpp
-
+if (index > maxlen)
+{
+	maxlen = index;
+	strcpy(maxbuf, maxbuf2);
+	maxbuf[index] = '\0';
+	maxbuf2[0] = buf[i];
+	index = 1;
+}
+else
+{
+	maxbuf2[0] = buf[i];
+	index = 1;
+}
 ```
 
 ## 选项
@@ -65,17 +121,48 @@ int main()
 ### A
 
 ```cpp
-
+if (index > maxlen)
+{
+	maxlen = index;
+	strcpy(maxbuf, maxbuf2);
+	maxbuf[index] = '\0';
+	maxbuf2[0] = buf[i];
+	index = 1;
+}
 ```
 
 ### B
 
 ```cpp
-
+if (index > maxlen)
+{
+	maxlen = index;
+	strcpy(maxbuf, maxbuf2);
+	maxbuf[index] = '\0';
+	maxbuf2[0] = buf[i];
+	index++;
+}
+else
+{
+	maxbuf2[0] = buf[i];
+	index++;
+}
 ```
 
 ### C
 
 ```cpp
-
+if (index > maxlen)
+{
+	maxlen = index;
+	strcpy(maxbuf, maxbuf2);
+	maxbuf[index] = '\0';
+	maxbuf2[0] = buf[i];
+	index = 0;
+}
+else
+{
+	maxbuf2[0] = buf[i];
+	index = 0;
+}
 ```
\ No newline at end of file

data/2.dailycode中阶/1.cpp/21.exercises/solution.md

@@ -2,6 +2,28 @@
 
 举例如下：一个数组{915,941,960,976,992,1015,1034,1050,1073,1089,1115,1131,1150,1166,1182,1208,1227};目标值假设是1000，最接近元素为992，下标为4
 
+以下程序实现了这一功能，请你填补空白处内容：
+
+```cpp
+#include <stdio.h>
+int main()
+{
+    int min = (1 << 31) - 1;
+    int idx = 0;
+    int arr[] = {915, 941, 960, 976, 992, 1015, 1034, 1050, 1073, 1089, 1115, 1131, 1150, 1166, 1182, 1208, 1227};
+    int n = 1000;
+    for (int i = 0; i < sizeof(arr) / sizeof(int); i++)
+    {
+        int diff = arr[i] - n;
+        if (diff < 0)
+            diff = -diff;
+        _________________;
+    }
+    printf("最接近的是%d 下标是%d", arr[idx], idx);
+    return 0;
+}
+```
+
 ## template
 
 ```cpp
@@ -10,12 +32,13 @@ int main()
 {
     int min = (1 << 31) - 1;
     int idx = 0;
-	int arr[] = {915,941,960,976,992,1015,1034,1050,1073,1089,1115,1131,1150,1166,1182,1208,1227};
+    int arr[] = {915, 941, 960, 976, 992, 1015, 1034, 1050, 1073, 1089, 1115, 1131, 1150, 1166, 1182, 1208, 1227};
     int n = 1000;
     for (int i = 0; i < sizeof(arr) / sizeof(int); i++)
     {
         int diff = arr[i] - n;
-		if (diff < 0) diff = -diff;
+        if (diff < 0)
+            diff = -diff;
         if (diff < min)
         {
             min = diff;
@@ -30,7 +53,11 @@ int main()
 ## 答案
 
 ```cpp
-
+if (diff < min)
+{
+	min = diff;
+	idx = i;
+}
 ```
 
 ## 选项
@@ -38,17 +65,29 @@ int main()
 ### A
 
 ```cpp
-
+if (diff > min)
+{
+	min = diff;
+	idx = i;
+}
 ```
 
 ### B
 
 ```cpp
-
+if (diff >= min)
+{
+	min = diff;
+	idx = i;
+}
 ```
 
 ### C
 
 ```cpp
-
+if (diff == min)
+{
+	min = diff;
+	idx = i;
+}
 ```
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