update

src/2/P1082.cpp

@@ -0,0 +1,32 @@
+/*
+ax%b=1
+ax+by=1
+*/
+#include <cstdint>
+#include <iostream>
+
+using ll = int64_t;
+
+ll a,b,x,y;
+
+ll exgcd(ll a,ll b){
+    if(b==0){
+        x=1,y=0;
+        return a;
+    }
+    
+    ll d = exgcd(b,a%b);
+    ll tmpy = y;
+    y=x-a/b*y;
+    x=tmpy;
+    return d;
+}
+
+int main(){
+    std::cin>>a>>b;
+    exgcd(a,b);
+    while (x<0) {
+        x=(x%b+b)%b;
+    }
+    std::cout<<x<<'\n';
+}

src/2/P1516.cpp

@@ -0,0 +1,21 @@
+#include <cstdint>
+#include <iostream>
+
+using ll = int64_t;
+
+
+int main(){
+    ll x,y,m,n,L;
+    std::cin>>x>>y>>m>>n>>L;
+    if(x==y){
+        std::cout<<0<<'\n';
+        return 0;
+    }else{
+        if(m==n){
+            std::cout<<"Impossible\n";
+            return 0;
+        }
+    }
+
+    
+}

src/2/P2613.cpp

@@ -0,0 +1,11 @@
+#include <cstdint>
+#include <iostream>
+
+using ll = int64_t;
+
+ll a,b;
+
+int main(){
+    std::cin>>a>>b;
+    
+}

src/2/P5656.cpp

@@ -0,0 +1,38 @@
+#include <cstdint>
+#include <iostream>
+#include <istream>
+
+using ll = int64_t;
+
+ll T;
+
+ll exgcd(ll a,ll b,ll&x,ll&y){
+    if(b==0){
+        x=1,y=0;
+        return a;
+    }
+    ll d = exgcd(b,a%b,x,y);
+    ll tmpy = y;
+    y = x-(a/b)*y;
+    x=tmpy;
+    return d;
+}
+
+int main(){
+    // std::iostream::sync_with_stdio(false);
+    // std::cin.tie(nullptr),std::cout.tie(nullptr);
+    std::cin>>T;
+
+    while(T--){
+        ll a,b,c;
+        std::cin>>a>>b>>c;
+        ll x,y;
+        ll g{exgcd(a,b,x,y)};
+        if(c%g!=0){
+            std::cout<<-1<<'\n';
+            continue;
+        }
+        ll f = c/g;
+        
+    }
+}