diff --git a/LongestSubSequence.c b/LongestSubSequence.c
new file mode 100644
index 00000000..bf2e7e54
--- /dev/null
+++ b/LongestSubSequence.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int* longestSubsequence(int* ARRAY, int LENGTH, int**RESULT,int* leRESULT_LENGTH){
+	if(LENGTH<=1){
+		*RESULT=ARRAY;
+		*leRESULT_LENGTH=LENGTH;
+	
+	}
+	else{
+		int PIVOT=ARRAY[0],n;
+		int* LongestSub=NULL;
+		longestSubsequence(ARRAY+1,LENGTH-1,&LongestSub,&n);
+		if (PIVOT<=LongestSub[0]){
+			int *newArray=(int *)realloc(NULL,(n+1)*sizeof(int));
+			int i;
+			newArray[0]=PIVOT;
+			for(i=1;i<n+1;i++)
+				newArray[i]=LongestSub[i-1];
+			*RESULT = newArray;
+			*leRESULT_LENGTH = n+1;
+
+		}
+		else{
+
+			*RESULT=LongestSub;
+			*leRESULT_LENGTH=n;
+		}
+	}
+}
+
+void longestSub(int* ARRAY,int ARRAY_LENGTH, int** RESULT,int* RESULT_LENGTH){	//RESULT and RESULT_LENGTH will be modified by their pointers
+	
+	if(ARRAY_LENGTH<=1){
+		*RESULT=ARRAY;
+		*RESULT_LENGTH=ARRAY_LENGTH;
+	}
+	else{
+		int PIVOT=ARRAY[0];													
+		int *maxi=NULL;														
+		int maxi_length=0,i,j;												
+		int TEMPORARY_ARRAY_LENGTH=0, *TEMPORARY_ARRAY=NULL;
+		int *LS_RESULT=NULL, LS_RESULT_length;
+
+		for(i=1;i<ARRAY_LENGTH;i++){
+			if (ARRAY[i]<PIVOT){
+				
+				TEMPORARY_ARRAY_LENGTH=0;
+				TEMPORARY_ARRAY=NULL;
+
+				for(j=i+1;j<ARRAY_LENGTH;j++){
+					if(ARRAY[j]>=ARRAY[i]){
+
+						TEMPORARY_ARRAY_LENGTH++;
+						TEMPORARY_ARRAY=(int *)realloc(TEMPORARY_ARRAY,TEMPORARY_ARRAY_LENGTH*sizeof(int));
+						TEMPORARY_ARRAY[TEMPORARY_ARRAY_LENGTH-1]=ARRAY[j];
+					}
+				}
+
+				LS_RESULT=NULL;
+				LS_RESULT_length=0;
+				longestSub(TEMPORARY_ARRAY,TEMPORARY_ARRAY_LENGTH,&LS_RESULT,&LS_RESULT_length);
+				if(maxi_length<LS_RESULT_length+1){
+
+					maxi_length=LS_RESULT_length+1;
+					maxi=(int*)realloc(maxi,(maxi_length)*sizeof(int));
+					maxi[0]=ARRAY[i];
+
+					for(i=1;i<maxi_length;i++)
+						maxi[i]=LS_RESULT[i-1];	
+				}
+			}
+		}
+
+		TEMPORARY_ARRAY=NULL;
+		TEMPORARY_ARRAY_LENGTH=0;
+		for(i=1;i<ARRAY_LENGTH;i++){
+
+			if(ARRAY[i]>=PIVOT){
+				TEMPORARY_ARRAY_LENGTH++;
+				TEMPORARY_ARRAY=(int *)realloc(TEMPORARY_ARRAY,TEMPORARY_ARRAY_LENGTH*sizeof(int));
+				TEMPORARY_ARRAY[TEMPORARY_ARRAY_LENGTH-1]=ARRAY[i];
+			}
+		}
+
+		longestSub(TEMPORARY_ARRAY,TEMPORARY_ARRAY_LENGTH,&LS_RESULT,&LS_RESULT_length);
+		if(LS_RESULT_length+1>maxi_length){
+			
+			maxi_length=LS_RESULT_length+1;
+			maxi=(int*)realloc(maxi,(maxi_length)*sizeof(int));
+			maxi[0]=PIVOT;
+			for(i=1;i<maxi_length;i++)
+				maxi[i]=LS_RESULT[i-1];
+		}
+		*RESULT=maxi;
+		*RESULT_LENGTH=maxi_length;
+	}
+	
+
+}
+
+int main(){
+
+	int *example=NULL;
+	int n,i;
+	int t[9]={10, 22, 9, 33, 21, 50, 41, 60, 80};
+	//Il y'a un problème au cas où on a un maximum au milieu
+	longestSub(t,9,&example,&n);
+	printf("longueur: %d\n",n);
+	for(i=0;i<n;i++)
+		printf("%d ",example[i]);
+	printf("\n");
+
+	return 0;
+}
\ No newline at end of file