View Compilation Error

0_0_35767603_15342.c:6:1: error: unknown type name 'bool'
 bool judge(int sta){
 ^
0_0_35767603_15342.c: In function 'judge':
0_0_35767603_15342.c:9:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int i=0; (1<<i)<=sta; i++)
     ^
0_0_35767603_15342.c:9:5: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your code
0_0_35767603_15342.c: In function 'dfs':
0_0_35767603_15342.c:27:5: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
     for(int s=sta-1;s>0; s=(s-1)&sta){
     ^
0_0_35767603_15342.c: In function 'main':
0_0_35767603_15342.c:44:9: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
         for(int i=(1<<len)-1; i>0; i--){
         ^