ansi fait

Pierre Cwik
1 parent 070a61d4
Showing 3 changed files with 52 additions and 0 deletions Show diff stats
a.out
ansi.c
derniers_exos.c
@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#define erreur(...) { fprintf(stderr,__VA_ARGS__) ; exit(EXIT_FAILURE); }
+int32_t premier(uint32_t n){
+bool crible[n*n+1];
+for(uint32_t i=0;i<=n*n;i++) crible[i]=true;
+for(uint32_t i=2;i<=n;i++)
+  if(crible[i]){
+    uint32_t j=i*i;
+    while(j<=n*n){ crible[j]=false; j += i; }
+    }
+int32_t result=-1;
+for(int32_t i=n*n;i>=0;i--) if(crible[i]){ result=i; break; }
+return result;
+}
+int main(void){
+uint32_t n;
+if(scanf("%d",&n)!=1) erreur("Echec de lecture du nombre\n");
+printf("premier -> %d\n",premier(n));
+return 0;
+}
+ 
@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#define erreur(message) { fprintf(stderr,message) ; exit(EXIT_FAILURE); }
+int premier(int n){
+int taille=n*n+1;
+int result=-1;
+  int *crible = malloc( taille * sizeof(int) );
+int i;
+for(i=0;i<=n*n;i++) crible[i]=true;
+for(i=2;i<=n;i++)
+  if(crible[i]){
+    int j=i*i;
+    while(j<=n*n){ crible[j]=false; j += i; }
+    }
+for(i=n*n;i>=0;i--) if(crible[i]){ result=i; break; }
+return result;
+}
+
+int main(void){
+int n;									
+if(scanf("%d",&n)!=1) erreur("Echec de lecture du nombre\n");
+printf("premier -> %d\n",premier(n));
+return 0;
+}
+
+