diff --git a/13307130414/assignment11/GREAT SWERC.cpp b/13307130414/assignment11/GREAT SWERC.cpp
new file mode 100644
index 0000000..2305401
--- /dev/null
+++ b/13307130414/assignment11/GREAT SWERC.cpp	
@@ -0,0 +1,74 @@
+#include <iostream>
+#include <cstring>
+using namespace std;
+
+bool str[26]; // to mark if a letter has existed
+bool num[10]; // to mark if a number is used
+string buf[10];
+int a[10];
+int cnt; // count how many different characters
+int ans;
+
+struct Node {
+    char c;
+    int n;
+    bool flag; // to mark if this letter is the leftmost one
+    Node() : flag(false) {}
+} node[10];
+
+bool check() {
+    for (int i = 0; i < cnt; i++) {
+        if (node[i].flag == true && a[i] == 0)
+            return false;
+    }
+    int temp = 0;
+    for (int i = 0; i < cnt; i++)
+        temp += a[i] * node[i].n;
+    if (temp == 0) return true;
+    else return false;
+}
+
+void dfs(int i) {
+    if (i > cnt) return;
+    for(int j = 0; j < 10; j++) {
+        if (i == 0) memset(num, false, sizeof(num));
+        if (num[j] == true) continue;
+        a[i] = j;
+        num[j] = true;
+        if (i == cnt-1 && check()) ans++;
+        dfs(i+1);
+        num[j] = false;
+    }
+}
+
+int main() {
+    int n;
+    cin >> n;
+    memset(str, false, sizeof(str));
+    cnt = 0;
+    ans = 0;
+    for (int i = 0; i < n; i++)
+        cin >> buf[i];
+    for (int i = 0; i < n; i++) {
+        for (int j = 0; j < buf[i].length(); j++) {
+            int t;
+            if (str[buf[i][j]-'A'] == true) {
+                for (t = 0; node[t].c != buf[i][j]; t++) ;
+            }
+            else {
+                t = cnt;
+                str[buf[i][j]-'A'] = true;
+                cnt++;
+            }
+            node[t].c = buf[i][j];
+            int temp = 1;
+            for (int l = 0; l < buf[i].length()-j-1; l++)
+                temp *= 10;
+            if (i != n-1) node[t].n += temp;
+            else node[t].n -= temp;
+            if (j == 0) node[t].flag = true;
+        }
+    }
+    dfs(0);
+    cout << ans << endl;
+}
diff --git a/13307130414/assignment11/POJ 3364 Black and white painting.cpp b/13307130414/assignment11/POJ 3364 Black and white painting.cpp
new file mode 100644
index 0000000..748becf
--- /dev/null
+++ b/13307130414/assignment11/POJ 3364 Black and white painting.cpp	
@@ -0,0 +1,25 @@
+#include <iostream>
+#include <cstdio>
+using namespace std;
+
+int main() {
+    //freopen("3364.txt", "r", stdin);
+    int n,m,c;
+    while (1) {
+        cin >> n >> m >> c;
+        if (n == 0 && m == 0 && c == 0) return 0;
+        if (n < 8 || m < 8) {
+            cout << "0" << endl;
+            continue;
+        }
+        int ans = 0;
+        if (c == 1) {
+            ans = ((m-7)*(n-7)+1)/2;
+        }
+        else {
+            ans = ((m-7)*(n-1-7)+1)/2;
+            ans += (m-7)/2;
+        }
+        cout << ans << endl;
+    }
+}
diff --git a/13307130414/assignment11/POJ 3366 Deli Deli.cpp b/13307130414/assignment11/POJ 3366 Deli Deli.cpp
new file mode 100644
index 0000000..6fd4bf8
--- /dev/null
+++ b/13307130414/assignment11/POJ 3366 Deli Deli.cpp	
@@ -0,0 +1,76 @@
+#include <iostream>
+#include <cstdio>
+#include <cstring>
+using namespace std;
+
+const int H = 100007;
+int hashtable[H];
+
+struct Node {
+    char before[25];
+    char after[25];
+    int next;
+    Node() : next(-1) {}
+} node[25];
+
+int ELFhash(char* key) {
+    unsigned long g,h=0;
+    while(*key)
+    {
+        h=(h<<4)+*key++;
+        g=h & 0xf0000000L;
+        if(g) h^=g>>24;
+        h&=~g;
+    }
+    return h%H;
+}
+
+void inserthash(char *s, int i) {
+    int h = ELFhash(s);
+    node[i].next = hashtable[h];
+    hashtable[h] = i;
+}
+
+int searchhash(char *s) {
+    int h = ELFhash(s);
+    int next = hashtable[h];
+    while (next != -1) {
+        if (!strcmp(node[next].before, s)) return next;
+        next = node[next].next;
+    }
+    return -1;
+}
+
+int main() {
+    //freopen("3366.txt", "r", stdin);
+    int l,n;
+    cin >> l >> n;
+    memset(hashtable, -1, sizeof(hashtable));
+    for (int i = 0; i < l; i++) {
+        cin >> node[i].before >> node[i].after;
+        inserthash(node[i].before, i);
+    }
+    for (int i = 0; i < n; i++) {
+        char str[25];
+        cin >> str;
+        if (searchhash(str) != -1) {
+            cout << node[searchhash(str)].after << endl;
+        }
+        else if (str[strlen(str) - 1] == 'y') {
+            if (strlen(str) > 1 && str[strlen(str) -2] == 'a' || str[strlen(str) -2] == 'e' ||
+                str[strlen(str) -2] == 'i' || str[strlen(str) -2] == 'u' || str[strlen(str) -2] == 'o')
+                cout << str << 's' << endl;
+            else {
+                str[strlen(str) - 1] = '\0';
+                cout << str << "ies" << endl;
+            }
+        }
+        else if (str[strlen(str)-1] == 'o' || str[strlen(str)-1] == 's' || str[strlen(str)-1] == 'x'
+                 || (str[strlen(str)-1] == 'h' && (str[strlen(str)-2] == 'c' || str[strlen(str)-2] == 's'))) {
+            cout << str << "es" << endl;
+        }
+        else
+            cout << str << "s" << endl;
+    }
+    return 0;
+}
diff --git a/13307130414/assignment11/POJ 3367 Expressions.cpp b/13307130414/assignment11/POJ 3367 Expressions.cpp
new file mode 100644
index 0000000..7eeb9e3
--- /dev/null
+++ b/13307130414/assignment11/POJ 3367 Expressions.cpp	
@@ -0,0 +1,65 @@
+#include <iostream>
+#include <vector>
+#include <queue>
+#include <string>
+#include <cstring>
+#include <cctype>
+#include <cstdio>
+#include <algorithm>
+using namespace std;
+
+const int N = 10010;
+
+vector <int> v;
+char str[N];
+pair <int, int> p[N];
+int len;
+
+void init() {
+    len = strlen(str);
+    for (int i = 0; i < len; i++)
+        p[i].first = p[i].second = -1;
+    v.clear();
+}
+
+void output() {
+    string ans = "";
+    queue <int> q;
+    q.push(len-1);
+    while(!q.empty()) {
+        int t = q.front();
+        q.pop();
+        ans += str[t];
+        if (p[t].first != -1) {
+            q.push(p[t].first);
+            q.push(p[t].second);
+        }
+    }
+    reverse(ans.begin(), ans.end());
+    cout << ans << endl;
+}
+
+int main() {
+    //freopen("3367.txt", "r", stdin);
+    int cas;
+    cin >> cas;
+    while(cas--) {
+        cin >> str;
+        init();
+        for (int i = 0; i < len; i++) {
+            if (islower(str[i])) {
+                v.push_back(i);
+            }
+            else {
+                int a = v.back();
+                v.pop_back();
+                int b = v.back();
+                v.pop_back();
+                p[i] = make_pair(b,a);
+                v.push_back(i);
+                //cout << str[i] << ' ' << str[b] << ' ' << str[a] << endl;
+            }
+        }
+        output();
+    }
+}
diff --git a/13307130414/assignment11/POJ 3370 Halloween treats.cpp b/13307130414/assignment11/POJ 3370 Halloween treats.cpp
new file mode 100644
index 0000000..09364ed
--- /dev/null
+++ b/13307130414/assignment11/POJ 3370 Halloween treats.cpp	
@@ -0,0 +1,44 @@
+#include <iostream>
+#include <cstdio>
+#include <cstring>
+using namespace std;
+
+int mod[100010];
+int a[100010];
+
+int main() {
+    int c,n;
+    while(1) {
+        scanf("%d%d", &c, &n);
+        if (c == 0 && n == 0) return 0;
+        memset(mod, -1, sizeof(mod));
+        long long sum = 0;
+        for (int i = 0; i < n; i++)
+            scanf("%d", &a[i]);
+        int i;
+        for (i = 0; i < n; i++) {
+            sum += a[i];
+            if (sum%c == 0) {
+                for (int j = 1; j <= i+1; j++) {
+                    printf("%d", j);
+                    if (j != i+1)
+                        printf(" ");
+                }
+                printf("\n");
+                break;
+            }
+            else if (mod[sum%c] != -1) {
+                for (int j = mod[sum%c]+1; j <= i+1; j++) {
+                    printf("%d", j);
+                    if (j != i+1)
+                        printf(" ");
+                }
+                printf("\n");
+                break;
+            }
+            else
+                mod[sum%c] = i+1;
+        }
+        if (i == n) printf("no sweets\n");
+    }
+}