Allocation of Memory 解题报告

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　　第1484题，Allocation of Memory，题目链接http://202.197.224.59/OnlineJudge/index.php/problem/read/id/1484，直接暴力模拟。收到Quit信号，即清空内存为0。否则，察看如果有空间，若有，直接使用，赋值为pid，输出内存地址；否则，碎片整理，再看是否有空间，若有，直接使用，赋值为pid，输出内存地址；若无，输出-1。

　　C语言代码如下：

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <stdbool.h>#define MAX_MEMORY 510typedef int COUNT;int memory[MAX_MEMORY];int maxMemory;bool canAlloc( int start, int apply ){COUNT i;for ( i = 0 ; i < apply ; i ++ ){if ( start + i > maxMemory )return false;if ( memory[start+i] != 0 )return false;}return true;}void defrag(void){COUNT i, j;for ( i = 1 ; i <= maxMemory ; i ++ ){if ( memory[i] == 0 ){for ( j = i + 1 ; j <= maxMemory ; j ++ ){if ( memory[j] != 0 ){memory[i] = memory[j];memory[j] = 0;break;}}}}}int alloc( int pid, int apply ){COUNT i, j;for ( i = 1 ; i <= maxMemory ; i ++ ){if ( memory[i] == 0 ){if ( canAlloc(i, apply) ){for ( j = 0 ; j < apply ; j ++ )memory[i+j] = pid;return i;}}}defrag();for ( i = 1 ; i <= maxMemory ; i ++ ){if ( memory[i] == 0 ){if ( canAlloc(i, apply) ){for ( j = 0 ; j < apply ; j ++ )memory[i+j] = pid;return i;}}}return -1;}void killprocess( int pid ){COUNT i;for ( i = 1; i <= maxMemory ; i ++ ){if ( memory[i] == pid )memory[i] = 0;}}int main (void){int testcases;COUNT i, j;char cmd[12];int pid, apply;int instructions;scanf( "%d", &testcases );for ( i = 1 ; i <= testcases ; i ++ ){scanf( "%d%d", &maxMemory, &instructions );memset( memory, 0, sizeof(memory) );printf( "Case %d:\n", i );for ( j = 0 ; j < instructions ; j ++ ){scanf( "%s", cmd );if ( !strcmp( cmd, "New" ) ){scanf( "%d%d", &pid, &apply );printf( "%d\n", alloc( pid, apply ) );}else{scanf( "%d", &pid );killprocess( pid );}}}return EXIT_SUCCESS;}