Queue 구현코드 (큐)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174

#include <stdio.h> #define SZ 5 int queue[5]; int front = 0; int rear = 0; int isEmpty() { return (front == rear); } int isFull() { return ((rear + 1) % SZ == front); } // put the data d into the queue // only if there is room. void enque(int d) { if (isFull() == 1) { return; } queue[rear] = d; // consider that the queue is circular,, rear = (rear + 1) % SZ; return; } // take out one item from the queue // returns -999 if the queue is empty. int deque() { if (isEmpty() == 1) { return -999; } { int temp = queue[front]; front = (front + 1) % SZ; return temp; } } int main(void) { // test case for the full queue for (int i = 0; i <10; i++) { enque(i); } for (int i = 0; i < 10; i++) { printf("%d\n", deque()); } #if 0 printf("%d\n", deque()); #endif #if 0 enque(3); enque(4); enque(5); printf("%d\n", deque()); printf("%d\n", deque()); printf("%d\n", deque()); #endif return 0; } #if 0 #include <stdio.h> #define SZ 5 int stack[5]; int top = -1; // check the stack is empty // it returns 1 if so, // returns 0 otherwise int isEmpty() { return (top == -1); } // check the stack is full // it returns 1 if so, // returns 0 otherwise int isFull() { // (SZ-1) is the last index of the stack return (top == (SZ - 1)); } // put the data d into the stack // if the stack is full, do nothing, just return void push(int d) { if (isFull() == 1) { return; } top++; // because the initial value of top is -1 stack[top] = d; // stack[++top] = d; the above two lines can be // written in one line. return; } // take out one item from the stack // returns -999 if the stack is empty. int pop() { if (isEmpty() == 1) { return -999; // -999 means the stack is empty. } top--; return stack[top + 1]; /* the above two lines mean the following. { int temp = stack[top]; top--; return temp; } */ } int main(void) { #if 0 // test case forf the full stack for (int i = 0; i <10; i++) { push(i); } printf("%d\n", pop()); #endif #if 0 // test case for the empty stack printf("%d \n", pop()); #endif #if 0 push(1); push(2); push(3); for (int i = 0; i < 3; i++) { printf("%d\n", pop()); } #endif return 0; } #endif