struggled on test

Olympiad Practise/week last/.cph/.oly21practice47.cpp_0709a620a83c8c9c48b6090002d4f3c8.prob

@@ -0,0 +1 @@
+{"name":"Local: oly21practice47","url":"c:\\My Files\\GitHub\\Practise\\Olympiad Practise\\week last\\oly21practice47.cpp","tests":[{"id":1623525100682,"input":"world\nword","output":"Yes"},{"id":1623525106799,"input":"snekee\nsnuke","output":"No"},{"id":1623525110835,"input":"hello\nhello","output":"Yes"}],"interactive":false,"memoryLimit":1024,"timeLimit":3000,"srcPath":"c:\\My Files\\GitHub\\Practise\\Olympiad Practise\\week last\\oly21practice47.cpp","group":"local","local":true}

Olympiad Practise/week last/.cph/.oly21practice55.cpp_4f1de5a06373a025e0334cea02715a4c.prob

@@ -0,0 +1 @@
+{"name":"Local: oly21practice55","url":"c:\\My Files\\GitHub\\Practise\\Olympiad Practise\\week last\\oly21practice55.cpp","tests":[{"id":1623525803447,"input":"banana","output":"c"},{"id":1623525809009,"input":"abcdefghijklmnopqrstuvwxyz","output":"aa"},{"id":1623526010495,"input":"aabbccddeeffgghhiiijjkkllmmnnooppqqrrssttuuvvwwxxyyzz","output":""}],"interactive":false,"memoryLimit":1024,"timeLimit":3000,"srcPath":"c:\\My Files\\GitHub\\Practise\\Olympiad Practise\\week last\\oly21practice55.cpp","group":"local","local":true}

Olympiad Practise/week last/oly21practice47.cpp

@@ -0,0 +1,57 @@
+#include <bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+typedef unsigned long long ull;
+typedef long double ld;
+typedef pair<int, int> pi;
+typedef pair<ll, int> pli;
+typedef pair<int, ll> pil;
+typedef pair<ll, ll> pl;
+typedef pair<ld, ld> pd;
+
+typedef vector<int> vi;
+typedef vector<ld> vd;
+typedef vector<ll> vl;
+typedef vector<pi> vpi;
+typedef vector<pl> vpl;
+
+#define INF 0x3f3f3f3f            // for int
+#define LL_INF 0x3f3f3f3f3f3f3f3f // for ll
+#define sz(x) (int)(x).size()
+#define ms(x, y) memset(x, y, sizeof(x))
+#define mp make_pair
+#define pb push_back
+#define f first
+#define s second
+#define lb lower_bound
+#define ub upper_bound
+#define all(x) x.begin(), x.end()
+#define ins insert
+
+const int MOD = 1000000007, MX = 100000 + 5;
+string A, B;
+int main()
+{
+  cin >> A >> B;
+  if (!(A.size() == B.size() || A.size() - 1 == B.size()))
+  {
+    printf("No\n");
+    return 0;
+  }
+
+  bool err = false;
+  for (int i = 0; i < B.size(); i++)
+  {
+    if (A.at(i + err) != B.at(i))
+      if (!err)
+        err = true;
+      else
+      {
+        printf("No\n");
+        return 0;
+      }
+  }
+
+  printf("Yes\n");
+  return 0;
+}

Olympiad Practise/week last/oly21practice55.cpp

@@ -0,0 +1,85 @@
+#include <bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+typedef unsigned long long ull;
+typedef long double ld;
+typedef pair<int, int> pi;
+typedef pair<ll, int> pli;
+typedef pair<int, ll> pil;
+typedef pair<ll, ll> pl;
+typedef pair<ld, ld> pd;
+
+typedef vector<int> vi;
+typedef vector<ld> vd;
+typedef vector<ll> vl;
+typedef vector<pi> vpi;
+typedef vector<pl> vpl;
+
+#define INF 0x3f3f3f3f            // for int
+#define LL_INF 0x3f3f3f3f3f3f3f3f // for ll
+#define sz(x) (int)(x).size()
+#define ms(x, y) memset(x, y, sizeof(x))
+#define mp make_pair
+#define pb push_back
+#define f first
+#define s second
+#define lb lower_bound
+#define ub upper_bound
+#define all(x) x.begin(), x.end()
+#define ins insert
+
+const int MOD = 1000000007, MX = 500 + 5;
+
+char str[MX];
+vi revmap[256];
+
+bool freq[256];
+int freqc;
+
+int main()
+{
+  scanf("%s", str);
+  int slen = strlen(str);
+  for (int i = 0; i < slen; i++)
+  {
+    char c = str[i];
+    revmap[c].push_back(i);
+  }
+
+  int len = 1;
+  for (int c = 'a'; c <= 'z'; c++)
+  {
+    if(revmap[c].empty()){
+      printf("%c\n", c);
+      return 0;
+    }
+  }
+
+  for (int c = 'a'; c <= 'z'; c++){
+    freqc = 0;
+    for (int c2 = 'a'; c2 <= 'z'; c2++)
+      freq[c2] = 0;
+
+    for(int idx : revmap[c]){
+      if(idx == slen-1)continue;
+      if(!freq[str[idx+1]])
+        freqc++;
+      freq[str[idx+1]] = true;
+      if(freqc==26)break;
+    }
+    if(freqc==26)continue;
+    printf("%c", c);
+    for (int c2 = 'a'; c2 <= 'z'; c2++)
+    {
+      if(!freq[c2]){
+        printf("%c", c2);
+        break;
+      }
+    }
+    break;
+  }
+
+  printf("\n");
+
+  return 0;
+}