View Compilation Error

0_0_15303596_13000.c: In function 'qsort':
0_0_15303596_13000.c:16:5: error: expected expression before '/' token
     //printf("low=%d\n",low);
     ^
0_0_15303596_13000.c: In function 'main':
0_0_15303596_13000.c:51:13: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
             for(int i=0;i<n;i++)
             ^
0_0_15303596_13000.c:51:13: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_15303596_13000.c:57:21: error: redefinition of 'i'
             for(int i =1;i<n;i++)
                     ^
0_0_15303596_13000.c:51:21: note: previous definition of 'i' was here
             for(int i=0;i<n;i++)
                     ^
0_0_15303596_13000.c:57:13: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
             for(int i =1;i<n;i++)
             ^