View Compilation Error

0_0_15234220_27976.c: In function 'main':
0_0_15234220_27976.c:11:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for(int i=1;i<=N;i++)
         ^
0_0_15234220_27976.c:11:9: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_15234220_27976.c:39:17: error: expected expression before 'double'
             sum=double(m*s)+sum;
                 ^