（Problem 42）Coded triangle numbers

The n^th term of the sequence of triangle numbers is given by, t_n = ½n(n+1); so the first ten triangle numbers are:

1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...

By converting each letter in a word to a number corresponding to its alphabetical position and adding these values we form a word value. For example, the word value for SKY is 19 + 11 + 25 = 55 = t₁₀. If the word value is a triangle number then we shall call the word a triangle word.

Using words.txt (right click and 'Save Link/Target As...'), a 16K text file containing nearly two-thousand common English words, how many are triangle words?

题目大意：

三角形数序列中第 n 项的定义是： t_n = ½n(n+1); 因此前十个三角形数是:

1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...

通过将一个单词中每个字母在字母表中的位置值加起来，我们可以将一个单词转换为一个数。例如，单词SKY的值为19 + 11 + 25 = 55 = t₁₀。如果单词的值是一个三角形数，我们称这个单词为三角形单词。

words.txt (右键另存为)是一个16K的文本文件，包含将近两千个常用英语单词。在这个文件中，一共有多少个三角形词？

//（Problem 42）Coded triangle numbers

// Completed on Tue, 19 Nov 2013, 03:34

// Language: C11

//

// 版权所有（C）acutus   (mail: acutus@126.com)

// 博客地址：http://www.cnblogs.com/acutus/

#include <stdio.h>

#include <ctype.h>

#include <stdlib.h>

#include <stdbool.h>

#include <math.h>

bool test(int n)

{

    int m;

    m = (int)sqrt(n * );

    if(m * (m + ) ==  * n) return true;

    else return false;

}

int count(char * s)

{

    int i = ;

    int sum = ;

    while(s[i] != '\0') {

        sum += s[i] - 'A' + ;

        i++;

    }

    return sum;

}

void solve(void)

{

    FILE *fp;

    int i, j, k;

    char *s, c;

    int sum = ;

    char a[];

    fp = fopen("words.txt", "r");

    fseek(fp, , SEEK_END);

    int file_size;

    file_size = ftell(fp);

    fseek(fp, , SEEK_SET);

    s = (char*)malloc(file_size * sizeof(char));

    fread(s, sizeof(char), file_size, fp);

    i = j = k = ;

    while(i <= file_size) {

        c = s[i++];

        if(!isalpha(c)) {

            if(c == ',') {

                j = ;

                if(test(count(a)))  sum++;

                memset(a,'\0',  * sizeof(char));

            }

        } else {

            a[j++] = c;

        }

    }

    if(test(count(a)))  sum++;

    memset(a,'\0', * sizeof(char));

    printf("%d\n",sum);

}

int main(void)

{

    solve();

    return ;

}

Answer:

162

巴特西

（Problem 42）Coded triangle numbers

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