hihocoder 1110 正则表达式

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define maxn 105
int dp[maxn][maxn];
char s[maxn];

int check(int l, int r){
if(dp[l][r] != -1){
return dp[l][r];
}
if((s[l] == ')') || (s[l] == '*') || (s[l] == '|')){
return dp[l][r] = 0;
}
if(l == r){
if((s[l] == '1') || (s[l] == '0')){
return dp[l][l] = 1;
}
return dp[l][l] = 0;
}
if((s[l] == '(') && (s[r] == ')')){
if((check(l + 1, r - 1) == 1) && (r - l > 1)){
return dp[l][r] = 1;
}
//return dp[l][r] = 0; 在这里提前返回会WA，没想明白为啥
}
if(s[r] == '*'){
return dp[l][r] = check(l, r - 1);
}
for(int i = l; i < r; i++){
if(s[i] == '|'){
if((check(l, i - 1) == 1) && (check(i + 1, r) == 1)){
return dp[l][r] = 1;
}
}
if((check(l, i) == 1) && (check(i + 1, r) == 1)){
return dp[l][r] = 1;
}
}
return dp[l][r] = 0;
}

int main(){
int len;
while(scanf("%s", s) != EOF){
memset(dp, -1, sizeof(dp));
len = strlen(s);
if(check(0, len - 1) == 1){
printf("yes\n");
}else{
printf("no\n");
}
}
return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define maxn 105
char s[maxn];
bool dp[maxn][maxn];

int main(){
int i, j, k, m, len;
while(scanf("%s", s) != EOF){
memset(dp, false, sizeof(dp));
len = strlen(s);
for(i = 0; i < len; i++){
if((s[i] == '1') || (s[i] == '0')){
dp[i][i] = true;
}
}
for(k = 0; k < len; k++){
for(i = 0; i + k < len; i++){
j = i + k;
for(m = i; m <= j; m++){
if((m > i) && (s[m] == '|')){
dp[i][j] |= dp[i][m - 1] & dp[m + 1][j];
}
dp[i][j] |= dp[i][m] & dp[m + 1][j];
}
if((s[i] == '(') && (s[j] == ')')){
dp[i][j] |= dp[i + 1][j - 1];
}
if(s[j] == '*'){
dp[i][j] |= dp[i][j - 1];
}
}
}
if(dp[0][len - 1]){
printf("yes\n");
}else{
printf("no\n");
}
}
return 0;
}