diff --git a/.DS_Store b/.DS_Store
index 8ae7172..8bc830c 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/CodeForces/Chat Screenshots.cpp b/CodeForces/Chat Screenshots.cpp
new file mode 100644
index 0000000..3e656bf
--- /dev/null
+++ b/CodeForces/Chat Screenshots.cpp	
@@ -0,0 +1,51 @@
+#include <iostream>
+using namespace std;
+
+const int N = 200005;
+struct Edge{
+    int to, nxt;
+}g[N];
+int h[N], d[N], idx;
+int a[N], q[N];
+void add(int a,int b)
+{
+    g[++idx].to = b, g[idx].nxt = h[a], h[a] = idx;
+    d[b] ++;
+}
+int main()
+{
+    int n, k;
+    scanf("%d%d", &n, &k);
+    for (int i = 1; i <= n; i ++ )
+        h[i] = d[i] = 0;
+    idx = 0;
+    for (int i = 1;i <= k; i ++ )
+    {
+        for (int j = 1; j <= n; j ++ )
+            scanf("%d", &a[j]);
+        for (int j = 2; j < n; j ++ )
+            add(a[j], a[j + 1]);
+    }
+    int hh = 0, tt = -1;
+    for (int i = 1; i <= n; i ++ )
+        if (d[i] == 0)
+            q[ ++ tt] = i;
+    while (hh <= tt)
+    {
+        int t = q[hh ++];
+        for (int i = h[t]; i; i = g[i].nxt)
+        {
+            int j = g[i].to;
+            if ( -- d[j] == 0)
+                q[ ++ tt] = j;
+        }
+    }
+    for (int i = 1; i <= n; i ++ )
+        if (d[i] > 0)
+        {
+            cout << "NO";
+            return 0;
+        }
+    cout << "YES";
+    return 0;
+}
diff --git a/XSM OJ 重庆小码王集团OJ/.DS_Store b/XSM OJ 重庆小码王集团OJ/.DS_Store
new file mode 100644
index 0000000..d5255b7
Binary files /dev/null and b/XSM OJ 重庆小码王集团OJ/.DS_Store differ
diff --git a/XSM OJ 重庆小码王集团OJ/【字符串】石头剪子布.cpp b/XSM OJ 重庆小码王集团OJ/【字符串】石头剪子布.cpp
new file mode 100644
index 0000000..2f1e489
--- /dev/null
+++ b/XSM OJ 重庆小码王集团OJ/【字符串】石头剪子布.cpp	
@@ -0,0 +1,16 @@
+#include <iostream>
+using namespace std;
+
+signed main()
+{
+	int n;
+	cin >> n ;
+	for(int i = 1; i <= n; ++ i)
+	{
+		string s1, s2;
+		cin >> s1 >> s2 ;
+		if(s1 == "Rock" && s2 == "Scissors" || s1 == "Scissors" && s2 == "Paper" || s1 == "Paper" && s2 == "Rock") cout << "Player1" << endl ;
+		else if(s1 == s2) cout << "Tie" << endl ;
+		else cout << "Player2" << endl ;
+	}
+}
\ No newline at end of file
diff --git a/XSM OJ 重庆小码王集团OJ/希蒙的AC贴纸数.cpp b/XSM OJ 重庆小码王集团OJ/希蒙的AC贴纸数.cpp
new file mode 100644
index 0000000..0e45ba5
--- /dev/null
+++ b/XSM OJ 重庆小码王集团OJ/希蒙的AC贴纸数.cpp	
@@ -0,0 +1,21 @@
+#include <iostream>
+#include <cstdio>
+#define int long long
+using namespace std;
+
+signed main()
+{
+	char a[1005];
+	scanf("%[^\n]", &a);
+	int i = 0, cnt = 0;
+	while(a[i] != '\0')
+	{
+		if(((a[i] == 'A' && a[i + 1] == 'C') || a[i] == a[i + 1]) && a[i] != ' ')
+		{
+			cnt ++ ;
+		}
+		i ++ ;
+	}
+	cout << cnt ;
+	return 0;
+}
\ No newline at end of file
diff --git a/XSM OJ 重庆小码王集团OJ/开关灯.cpp b/XSM OJ 重庆小码王集团OJ/开关灯.cpp
new file mode 100644
index 0000000..00f3222
--- /dev/null
+++ b/XSM OJ 重庆小码王集团OJ/开关灯.cpp	
@@ -0,0 +1,15 @@
+#include <iostream>
+using namespace std;
+int main(){
+	int n;
+	cin >> n ;
+	if(n % 2 == 1)
+	{
+		cout << 1 ;
+	}
+	else
+	{
+		cout << 0 ;
+	}
+	return 0; 
+}
\ No newline at end of file
diff --git a/XSM OJ 重庆小码王集团OJ/数字组合.cpp b/XSM OJ 重庆小码王集团OJ/数字组合.cpp
index 5e2ac6d..8b605d7 100644
--- a/XSM OJ 重庆小码王集团OJ/数字组合.cpp	
+++ b/XSM OJ 重庆小码王集团OJ/数字组合.cpp	
@@ -1,12 +1,23 @@
-#include <bits/stdc++.h>
+#include <iostream>
+
 using namespace std;
-int main(){
-	int n;
-	cin >> n;
-	cout <<n<<n<<n<<"     "<<n<<n<<n<<"     "<<n<<n<<n<<"     "<<n<<n<<n<<endl;
-	cout <<"  "<<n<<"     "<<n<<" "<<n<<"     "<<"  "<<n<<"     "<<n<<" "<<n<<endl;
-	cout <<n<<n<<n<<"     "<<n<<" "<<n<<"     "<<n<<n<<n<<"     "<<n<<" "<<n<<endl;
-	cout <<n<<"  "<<"     "<<n<<" "<<n<<"     "<<n<<"  "<<"     "<<n<<" "<<n<<endl;
-	cout <<n<<n<<n<<"     "<<n<<n<<n<<"     "<<n<<n<<n<<"     "<<n<<n<<n<<endl;
-	return 0;
-} 
+
+int main() {
+    int N;
+    cin >> N;
+    
+    int count = 0;
+    for (int i = 0; i <= N; ++i) {
+        for (int j = 0; j <= N; ++j) {
+            for (int k = 0; k <= N; ++k) {
+                if (i != j && j != k && i != k && (i * 100 + j * 10 + k) % 2 != 0 && i != 0) {
+                    ++count;
+                }
+            }
+        }
+    }
+
+    cout << count << endl;
+
+    return 0;
+}
diff --git a/XSM OJ 重庆小码王集团OJ/求阴影面积.cpp b/XSM OJ 重庆小码王集团OJ/求阴影面积.cpp
new file mode 100644
index 0000000..087f970
--- /dev/null
+++ b/XSM OJ 重庆小码王集团OJ/求阴影面积.cpp	
@@ -0,0 +1,10 @@
+#include <iostream>
+using namespace std;
+
+int main()
+{
+	double a;
+	cin >> a ;
+	printf("%.2lf", a * a / 4);
+	return 0;
+}
\ No newline at end of file
diff --git a/XSM OJ 重庆小码王集团OJ/算天数.cpp b/XSM OJ 重庆小码王集团OJ/算天数.cpp
new file mode 100644
index 0000000..072e8d4
--- /dev/null
+++ b/XSM OJ 重庆小码王集团OJ/算天数.cpp	
@@ -0,0 +1,67 @@
+#include <iostream>
+using namespace std;
+
+
+bool isLeapYear(int year) {
+    if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0 && year % 3200 != 0)){
+        return true;
+	} 
+    else{
+        return false;
+    } 
+}
+
+int getDaysOfMonth(int year, int month) {
+	if(month == 1 || month == 3 || month == 5 || month == 7 || month == 8 || month == 10 || month == 12){ 
+        return 31;
+    } 
+    if(month == 4 || month == 6 || month == 9 || month == 11){
+		return 30;
+    }
+    if(month == 2){
+        if(isLeapYear(year)==1){
+            return 29;	
+		}else{
+			return 28;
+		}
+    }
+}
+// �����ӹ�Ԫ2021��1��1�����������ڵ�����
+int calcDays(int year, int month, int day) {
+    int days = 0;
+    for (int i = 2021; i < year; i++) {
+    	if(isLeapYear(i)==1){
+            	days +=366;	
+			}else{
+				days +=365;
+			}
+    }
+    for (int i = 1; i < month; i++) {
+        days += getDaysOfMonth(year, i);
+    }
+    days += day-1;
+    return days;
+}
+
+int calcWeekday(int days) {
+    days+=5;
+    days%=7;
+    if(days==0){
+        return 7;
+    }
+    return days;
+}
+
+int main() {
+    int year, month, day;
+    cin >> year >> month >> day;
+    
+    int days = calcDays(year, month, day);
+    int weekday = calcWeekday(days);
+    
+    cout << days << endl;
+    cout << '*' << weekday << endl;
+    
+    return 0;
+}
+
diff --git a/洛谷刷题/.DS_Store b/洛谷刷题/.DS_Store
new file mode 100644
index 0000000..5008ddf
Binary files /dev/null and b/洛谷刷题/.DS_Store differ
diff --git a/洛谷刷题/P1005 [NOIP2007 提高组] 矩阵取数游戏.cpp b/洛谷刷题/P1005 [NOIP2007 提高组] 矩阵取数游戏.cpp
new file mode 100644
index 0000000..9622aa0
--- /dev/null
+++ b/洛谷刷题/P1005 [NOIP2007 提高组] 矩阵取数游戏.cpp	
@@ -0,0 +1,96 @@
+#include <iostream>
+#include <cstdio>
+#include <algorithm>
+#include <cstring>
+#include <cmath>
+
+using namespace std;
+
+const int MAXN = 85, Mod = 10000;
+int n, m;
+int ar[MAXN];
+
+struct HP {
+	int p[505], len;
+	HP() {
+		memset(p, 0, sizeof p);
+		len = 0;
+	} 
+	void print() {
+		printf("%d", p[len]);  
+        for (int i = len - 1; i > 0; i--) {  
+            if (p[i] == 0) {
+				printf("0000"); 
+				continue;
+			}
+            for (int k = 10; k * p[i] < Mod; k *= 10) 
+				printf("0");
+            printf("%d", p[i]);
+        }
+	}
+} f[MAXN][MAXN], base[MAXN], ans;
+
+HP operator + (const HP &a, const HP &b) {
+	HP c; c.len = max(a.len, b.len); int x = 0;
+	for (int i = 1; i <= c.len; i++) {
+		c.p[i] = a.p[i] + b.p[i] + x;
+		x = c.p[i] / Mod;
+		c.p[i] %= Mod;
+	}
+	if (x > 0)
+		c.p[++c.len] = x;
+	return c;
+} //高精+高精 
+
+HP operator * (const HP &a, const int &b) {
+	HP c; c.len = a.len; int x = 0;
+	for (int i = 1; i <= c.len; i++) {
+		c.p[i] = a.p[i] * b + x;
+		x = c.p[i] / Mod;
+		c.p[i] %= Mod;
+	}
+	while (x > 0)
+		c.p[++c.len] = x % Mod, x /= Mod;
+	return c;
+} //高精*单精 
+
+HP max(const HP &a, const HP &b) {
+	if (a.len > b.len)
+		return a;
+	else if (a.len < b.len)
+		return b;
+	for (int i = a.len; i > 0; i--)
+		if (a.p[i] > b.p[i])
+			return a;
+		else if (a.p[i] < b.p[i])
+			return b;
+	return a;
+} //比较取最大值 
+
+void BaseTwo() {
+	base[0].p[1] = 1, base[0].len = 1;
+	for (int i = 1; i <= m + 2; i++){ //这里是m! m! m! 我TM写成n调了n年... 
+		base[i] = base[i - 1] * 2;
+	}
+} //预处理出2的幂 
+
+int main(void) {
+	scanf("%d%d", &n, &m);
+	BaseTwo();
+	while (n--) {
+		memset(f, 0, sizeof f);
+		for (int i = 1; i <= m; i++)
+			scanf("%d", &ar[i]);
+		for (int i = 1; i <= m; i++)
+			for (int j = m; j >= i; j--) { //因为终值是小区间，DP自然就从大区间开始 
+				f[i][j] = max(f[i][j], f[i - 1][j] + base[m - j + i - 1] * ar[i - 1]); 
+				f[i][j] = max(f[i][j], f[i][j + 1] + base[m - j + i - 1] * ar[j + 1]);
+			} //用结构体重载运算符写起来比较自然 
+		HP Max;
+		for (int i = 1; i <= m; i++)
+			Max = max(Max, f[i][i] + base[m] * ar[i]);
+		ans = ans + Max; //记录到总答案中 
+	}
+	ans.print(); //输出 
+	return 0;
+}