diff --git a/a2/program.c b/a2/program.c index a7e2c41..c44595b 100644 --- a/a2/program.c +++ b/a2/program.c @@ -9,6 +9,8 @@ struct stack{ int size; }stack; +///add bracket to stack + void push(char ch){ if(stack.size < 100){ stack.size++; @@ -16,7 +18,9 @@ void push(char ch){ } else exit(0); -} +} + +///if i have opening bracket in stack, then decrement size void pop(){ if(stack.size >= 0) @@ -25,6 +29,8 @@ void pop(){ exit(0); } +///compare brackets + bool find_pair(char a, char b){ if(a == '(' && b == ')') return true; @@ -36,8 +42,10 @@ bool find_pair(char a, char b){ return true; return false; - } + +///function to find right pair + char right_pair(char a){ char b; if(a == '(') @@ -52,6 +60,8 @@ char right_pair(char a){ return b; } +///find the last opening bracket in the stack + char gettop(){ return stack.data[stack.size]; } @@ -68,53 +78,60 @@ int main(){ int l = strlen(line); int i, j = -1, f = -1;; - char *l_bracket = calloc(l, sizeof(char)); - char *r_bracket = calloc(l, sizeof(char)); + char *o_bracket = calloc(l, sizeof(char)); + char *c_bracket = calloc(l, sizeof(char)); for(i = 0; i < l; i++){ if(line[i] == '{' || line[i] == '(' || line[i] == '[' || line[i] == '<'){ push(line[i]); j++; f++; - l_bracket[j] = gettop(); - r_bracket[f] = right_pair(l_bracket[j]); + o_bracket[j] = gettop(); //get opening bracket from the stack + c_bracket[f] = right_pair(o_bracket[j]); //get closing bracket } - if(line[i] == '}' || line[i] == ')' || line[i] == ']' || line[i] == '>'){ - if(stack.size == -1){ + if(line[i] == '}' || line[i] == ')' || line[i] == ']' || line[i] == '>'){ + + if(stack.size == -1){ //if there is no opening bracket in the stack printf("Unexpected closing bracket %c in %d\n", line[i], i); return 0; } - else if(!find_pair(gettop(), line[i])){ - printf("Crossed bracket %c in %d, expected %c \n", line[i], i, r_bracket[f]); + else if(!find_pair(gettop(), line[i])){ //if there is another closing bracket + printf("Crossed bracket %c in %d, expected %c \n", line[i], i, c_bracket[f]); return 0; } else{ - r_bracket[f] = 0; - f--; + c_bracket[f] = 0; //if closing bracket is correct then reducee array + f--; //if i didn't find a correct bracket, then keep it in the array pop(); } } } int begin = 0; - int end = strlen(r_bracket); + int end = strlen(c_bracket); int temp; + + //now i have all missing closing brackets in array + + //flip array while(begin < end){ - temp = r_bracket[begin]; - r_bracket[begin++] = r_bracket[--end]; - r_bracket[end] = temp; + temp = c_bracket[begin]; + c_bracket[begin++] = c_bracket[--end]; + c_bracket[end] = temp; } + //if program pop all opening brackets from the stack, then stack size must be -1; if(stack.size == -1){ printf("All brackets OK\n"); } + //if no, then program didn't find closing bracket else { - printf("Missing closing brackets: %s\n", r_bracket); + printf("Missing closing brackets: %s\n", c_bracket); } - free(l_bracket); - free(r_bracket); + free(o_bracket); + free(c_bracket); return 0; }