diff --git a/cpp/coroutine/c1.cpp b/cpp/coroutine/c1.cpp
index f3ed0e0..5c36f0a 100644
--- a/cpp/coroutine/c1.cpp
+++ b/cpp/coroutine/c1.cpp
@@ -71,7 +71,7 @@ struct example {
       value =v;
       return std::suspend_never{};
     }
-    std::suspend_always final_suspend(){
+    std::suspend_always final_suspend() noexcept{
       cout<<"@ finale_suspend is called\n";
       return std::suspend_always{};
     }
@@ -110,4 +110,4 @@ int main(){
     cout<<a.get()<<endl;
   }
 
-}
\ No newline at end of file
+}
diff --git a/cpp/coroutine/c3.cpp b/cpp/coroutine/c3.cpp
index 2a37d60..dba7f7f 100644
--- a/cpp/coroutine/c3.cpp
+++ b/cpp/coroutine/c3.cpp
@@ -39,7 +39,7 @@ struct example {
       value=v;
       return std::suspend_always{};
     }
-    auto final_suspend()->std::suspend_always{
+    auto final_suspend() noexcept ->std::suspend_always{
       return std::suspend_always{};
     }
     void unhandled_exception(){
@@ -67,7 +67,7 @@ struct awaitble_obj {
 
 example<int> await_routine(){
   awaitble_obj a = awaitble_obj();
-  for (int i=1;i<5;i++){
+  for (int i=1;i<100;i++){
     auto v = co_await a;
     co_yield v;
   }
diff --git a/cpp/coroutine/c5.cpp b/cpp/coroutine/c5.cpp
index eb0efd5..4e4e9e4 100644
--- a/cpp/coroutine/c5.cpp
+++ b/cpp/coroutine/c5.cpp
@@ -145,7 +145,7 @@ struct task
   {
     task get_return_object() { return {}; }
     std::suspend_never initial_suspend() { return {}; }
-    std::suspend_never final_suspend() { return {}; }
+    std::suspend_never final_suspend() noexcept { return {}; }
     void return_void() {}
     void unhandled_exception() {}
   };
@@ -186,4 +186,4 @@ task consumer()
 int main(){
   auto c = consumer();
   producer();
-}
\ No newline at end of file
+}
diff --git a/cpp/pi.cpp b/cpp/pi.cpp
index 2f58f39..cc923e2 100644
--- a/cpp/pi.cpp
+++ b/cpp/pi.cpp
@@ -1,132 +1,136 @@
-// this is a plain translation from pi.d 
+// this is a plain translation from pi.d
 // all rights reserved
-# include <string> 
-# include <vector> 
-# include <iostream> 
-# include <chrono>
+// g++ pi.cpp -O3 -std=c++11
+#include <chrono>
+#include <iostream>
+#include <string>
+#include <vector>
 using namespace std;
 
-const int LONG_TIME =4000;
+const int LONG_TIME = 4000;
 vector<char> p;
 vector<char> t;
 int q;
 
-int tiszero(){
+int tiszero() {
   int k;
-  for (k=0;k<=q;k++){
-    if (t[k]!=0) return false;
+  for (k = 0; k <= q; k++) {
+    if (t[k] != 0)
+      return false;
   }
   return true;
 }
 
-void mul4(){
-  int i,c,d;
-  d=c=0;
-  for (i=q;i>=0;i--){
-    d = (p[i]*4+c)%10;
-    c= (p[i]*4+c)/10;
-    p[i]= static_cast<char>(d);
+void mul4() {
+  int i, c, d;
+  d = c = 0;
+  for (i = q; i >= 0; i--) {
+    d = (p[i] * 4 + c) % 10;
+    c = (p[i] * 4 + c) / 10;
+    p[i] = static_cast<char>(d);
   }
 }
 
-void div4(){
-  int i,c,d=0;
-  for( int i=0;i<=q;i++){
-    c = (10*d +p[i])/4;
-    d= (10*d +p[i])%4;
-    p[i]= static_cast<char>(c);
+void div4() {
+  int i, c, d = 0;
+  for (int i = 0; i <= q; i++) {
+    c = (10 * d + p[i]) / 4;
+    d = (10 * d + p[i]) % 4;
+    p[i] = static_cast<char>(c);
   }
 }
-void div( int divisor){
-  int i,b;
-  int quotient,remainder=0;
-  for ( auto & x:t){
-    b= (10* remainder +x);
-    quotient = b/divisor;
-    remainder= b%divisor;
-    x= static_cast<char>(quotient);
+void div(int divisor) {
+  int i, b;
+  int quotient, remainder = 0;
+  for (auto &x : t) {
+    b = (10 * remainder + x);
+    quotient = b / divisor;
+    remainder = b % divisor;
+    x = static_cast<char>(quotient);
   }
 }
 
-void mul(int multiplier){
-  int b,i,carry=0,digit=0;
-  for ( i=q;i>=0;i--){
-    b= (t[i]*multiplier+carry);
-    digit=b%10;
-    carry= b/10;
-    t[i]= static_cast<char>(digit);
+void mul(int multiplier) {
+  int b, i, carry = 0, digit = 0;
+  for (i = q; i >= 0; i--) {
+    b = (t[i] * multiplier + carry);
+    digit = b % 10;
+    carry = b / 10;
+    t[i] = static_cast<char>(digit);
   }
 }
-void sub(){
+void sub() {
   int j;
-  for ( j=q;j>=0;j--){
-    if (p[j]<t[j]){
-      p[j] -=t[j]-10;
-      p[j-1]-=1;
-    }else {
-      p[j]-=t[j];
+  for (j = q; j >= 0; j--) {
+    if (p[j] < t[j]) {
+      p[j] -= t[j] - 10;
+      p[j - 1] -= 1;
+    } else {
+      p[j] -= t[j];
     }
   }
 }
 
-void add( ){
+void add() {
   int j;
-  for (j=q;j>=0;j--){
-    if ( t[j]+p[j]>9){
-      p[j]+=t[j]-10;
-      p[j-1]+=1;
-    }else {
-      p[j]+=t[j];
+  for (j = q; j >= 0; j--) {
+    if (t[j] + p[j] > 9) {
+      p[j] += t[j] - 10;
+      p[j - 1] += 1;
+    } else {
+      p[j] += t[j];
     }
   }
 }
 
-void arctan(int s){
+void arctan(int s) {
   int n;
-  t[0]=1;
+  t[0] = 1;
   div(s);
   add();
-  n=1;
+  n = 1;
   do {
     mul(n);
-    div(s*s);
-    div(n+=2);
-    if ( ((n-1)/2)%2==0){
+    div(s * s);
+    div(n += 2);
+    if (((n - 1) / 2) % 2 == 0) {
       add();
-    }else {
+    } else {
       sub();
     }
-  }while (!tiszero());
+  } while (!tiszero());
 }
 
-
-int main(int argc,char * argv[]){
-  if (argc==2){
-    q= atoi(argv[1]);
-  }else {
-    cout<< "usage: pi [precision]\n"; 
+int main(int argc, char *argv[]) {
+  if (argc == 2) {
+    q = atoi(argv[1]);
+  } else {
+    cout << "usage: pi [precision]\n";
     exit(55);
   }
-  if (q<0){
-    cout<<" precision too low\n";
-    q=3;
-  }else if (q>LONG_TIME){
-    cout<<" be patient to wait a while \n";
+  if (q < 0) {
+    cout << " precision too low\n";
+    q = 3;
+  } else if (q > LONG_TIME) {
+    cout << " be patient to wait a while \n";
   }
   q++;
-  p.resize(q+1);
-  t.resize(q+1);
+  p.resize(q + 1);
+  t.resize(q + 1);
   auto start_time = std::chrono::system_clock::now();
   arctan(2);
   arctan(3);
   mul4();
- auto end_time = std::chrono::system_clock::now();
+  auto end_time = std::chrono::system_clock::now();
   q--;
-  cout<<"pi = "<< static_cast<int>(p[0])<<".";
-  for( int i=1;i<=q;i++){
-    cout<<static_cast<int>(p[i]);
+  cout << "pi = " << static_cast<int>(p[0]) << ".";
+  for (int i = 1; i <= q; i++) {
+    cout << static_cast<int>(p[i]);
   }
-  cout<<"\n time is "<< std::chrono::duration_cast<std::chrono::seconds>(end_time-start_time).count()<< "s\n";
+  cout << "\n time is "
+       << std::chrono::duration_cast<std::chrono::seconds>(end_time -
+                                                           start_time)
+              .count()
+       << "s\n";
   return 0;
-
-}
\ No newline at end of file
+}
diff --git a/d/pi.d b/d/pi.d
index bab7b9c..faac700 100644
--- a/d/pi.d
+++ b/d/pi.d
@@ -1,5 +1,6 @@
-// this is from example of dmd 
-// all rights reserved to dmd  
+// this is from example of dmd
+// all rights reserved to dmd
+// ldc2 pi.d
 import std.stdio;
 import std.conv;
 import core.stdc.stdlib;
@@ -11,179 +12,154 @@ byte[] p;
 byte[] t;
 int q;
 
-int main(string[] args)
-{
-    time_t startime, endtime;
-    int i;
+int main(string[] args) {
+  time_t startime, endtime;
+  int i;
 
-    if (args.length == 2)
-    {
-        q = to!int(args[1]);
-    }
-    else
-    {
-        writeln("Usage: pi [precision]");
-        exit(55);
-    }
+  if (args.length == 2) {
+    q = to !int(args[1]);
+  } else {
+    writeln("Usage: pi [precision]");
+    exit(55);
+  }
 
-    if (q < 0)
-    {
-        writeln("Precision was too low, running with precision of 0.");
-        q = 0;
-    }
+  if (q < 0) {
+    writeln("Precision was too low, running with precision of 0.");
+    q = 0;
+  }
 
-    if (q > LONG_TIME)
-    {
-        writeln("Be prepared to wait a while...");
-    }
+  if (q > LONG_TIME) {
+    writeln("Be prepared to wait a while...");
+  }
 
-    // Compute one more digit than we display to compensate for rounding
-    q++;
+  // Compute one more digit than we display to compensate for rounding
+  q++;
 
-    p.length = q + 1;
-    t.length = q + 1;
+  p.length = q + 1;
+  t.length = q + 1;
 
-    /* compute pi */
-    core.stdc.time.time(&startime);
-    arctan(2);
-    arctan(3);
-    mul4();
-    core.stdc.time.time(&endtime);
+  /* compute pi */
+  core.stdc.time.time(&startime);
+  arctan(2);
+  arctan(3);
+  mul4();
+  core.stdc.time.time(&endtime);
 
-    // Return to the number of digits we want to display
-    q--;
+  // Return to the number of digits we want to display
+  q--;
 
-    /* print pi */
+  /* print pi */
 
-    writef("pi = %d.", cast(int) (p[0]));
+  writef("pi = %d.", cast(int)(p[0]));
 
-    for (i = 1; i <= q; i++)
-        writef("%d", cast(int) (p[i]));
+  for (i = 1; i <= q; i++)
+    writef("%d", cast(int)(p[i]));
 
-    writeln();
-    writefln("%s seconds to compute pi with a precision of %s digits.", endtime - startime, q);
+  writeln();
+  writefln("%s seconds to compute pi with a precision of %s digits.",
+           endtime - startime, q);
 
-    return 0;
+  return 0;
 }
 
-void arctan(int s)
-{
-    int n;
-
-    t[0] = 1;
-    div(s);     /* t[] = 1/s */
-    add();
-    n = 1;
-
-    do
-    {
-        mul(n);
-        div(s * s);
-        div(n += 2);
-
-        if (((n - 1) / 2) % 2 == 0)
-            add();
-        else
-            sub();
-    } while (!tiszero());
+void arctan(int s) {
+  int n;
+
+  t[0] = 1;
+  div(s); /* t[] = 1/s */
+  add();
+  n = 1;
+
+  do {
+    mul(n);
+    div(s * s);
+    div(n += 2);
+
+    if (((n - 1) / 2) % 2 == 0)
+      add();
+    else
+      sub();
+  } while (!tiszero());
 }
 
-void add()
-{
-    int j;
-
-    for (j = q; j >= 0; j--)
-    {
-        if (t[j] + p[j] > 9)
-        {
-            p[j]     += t[j] - 10;
-            p[j - 1] += 1;
-        }
-        else
-            p[j] += t[j];
-    }
+void add() {
+  int j;
+
+  for (j = q; j >= 0; j--) {
+    if (t[j] + p[j] > 9) {
+      p[j] += t[j] - 10;
+      p[j - 1] += 1;
+    } else
+      p[j] += t[j];
+  }
 }
 
-void sub()
-{
-    int j;
-
-    for (j = q; j >= 0; j--)
-    {
-        if (p[j] < t[j])
-        {
-            p[j]     -= t[j] - 10;
-            p[j - 1] -= 1;
-        }
-        else
-            p[j] -= t[j];
-    }
+void sub() {
+  int j;
 
+  for (j = q; j >= 0; j--) {
+    if (p[j] < t[j]) {
+      p[j] -= t[j] - 10;
+      p[j - 1] -= 1;
+    } else
+      p[j] -= t[j];
+  }
 }
 
-void mul(int multiplier)
-{
-    int b;
-    int i;
-    int carry = 0, digit = 0;
-
-    for (i = q; i >= 0; i--)
-    {
-        b     = (t[i] * multiplier + carry);
-        digit = b % 10;
-        carry = b / 10;
-        t[i]  = cast(byte) digit;
-    }
+void mul(int multiplier) {
+  int b;
+  int i;
+  int carry = 0, digit = 0;
+
+  for (i = q; i >= 0; i--) {
+    b = (t[i] * multiplier + carry);
+    digit = b % 10;
+    carry = b / 10;
+    t[i] = cast(byte) digit;
+  }
 }
 
 /* t[] /= l */
-void div(int divisor)
-{
-    int i, b;
-    int quotient, remainder = 0;
-
-    foreach (ref x; t)
-    {
-        b         = (10 * remainder + x);
-        quotient  = b / divisor;
-        remainder = b % divisor;
-        x         = cast(byte) quotient;
-    }
+void div(int divisor) {
+  int i, b;
+  int quotient, remainder = 0;
+
+  foreach (ref x; t) {
+    b = (10 * remainder + x);
+    quotient = b / divisor;
+    remainder = b % divisor;
+    x = cast(byte) quotient;
+  }
 }
 
-void div4()
-{
-    int i, c, d = 0;
+void div4() {
+  int i, c, d = 0;
 
-    for (i = 0; i <= q; i++)
-    {
-        c    = (10 * d + p[i]) / 4;
-        d    = (10 * d + p[i]) % 4;
-        p[i] = cast(byte) c;
-    }
+  for (i = 0; i <= q; i++) {
+    c = (10 * d + p[i]) / 4;
+    d = (10 * d + p[i]) % 4;
+    p[i] = cast(byte) c;
+  }
 }
 
-void mul4()
-{
-    int i, c, d;
+void mul4() {
+  int i, c, d;
 
-    d = c = 0;
+  d = c = 0;
 
-    for (i = q; i >= 0; i--)
-    {
-        d    = (p[i] * 4 + c) % 10;
-        c    = (p[i] * 4 + c) / 10;
-        p[i] = cast(byte) d;
-    }
+  for (i = q; i >= 0; i--) {
+    d = (p[i] * 4 + c) % 10;
+    c = (p[i] * 4 + c) / 10;
+    p[i] = cast(byte) d;
+  }
 }
 
-int tiszero()
-{
-    int k;
+int tiszero() {
+  int k;
 
-    for (k = 0; k <= q; k++)
-        if (t[k] != 0)
-            return false;
+  for (k = 0; k <= q; k++)
+    if (t[k] != 0)
+      return false;
 
-    return true;
+  return true;
 }
diff --git a/pdf/cpp/p080.cc b/pdf/cpp/p080.cc
deleted file mode 100644
index aae6b48..0000000
--- a/pdf/cpp/p080.cc
+++ /dev/null
@@ -1,26 +0,0 @@
-#include <stdio.h>
-#include <mpfr.h> 
-#include <math.h>
-
-// gcc p080.cc  -lmpfr -lgmp -lm 
-int main(){
-    mpfr_t s;
-    mpfr_init2(s,400);
-    int ans =0;
-    for (int d=2;d<=100;d=d+1){ 
-        int v= sqrt(d*1.0);
-        if (v*v==d) continue;
-        mpfr_set_d(s,d,MPFR_RNDD);
-        mpfr_sqrt(s,s,MPFR_RNDD);
-        //mpfr_out_str(stdout,10,0,s,MPFR_RNDD);
-        char *root2;
-        mpfr_exp_t e;
-        root2=mpfr_get_str(NULL,&e,10,0,s,MPFR_RNDD);
-        for(int i=0;i<100;i++) {
-            ans =ans + (root2[i]-'0');
-         }
-    
-    } 
-    printf("%d\n",ans);
-    mpfr_clear(s);
-}